Part 12

The "jack" (_Caran plumieri_) is found to be poisonous in some seasons of the year, and it is said that at such times two small red lumps appear in its gills. When they are suspected of being in a poisonous condition an experiment is tried upon a duck by giving her one of them to swallow, and if at that season it is poisonous the duck dies in about two hours. The "rock hind," or "smoky hind," after attaining a certain size becomes most unwholesome, and often infested with parasites. Numerous instances of severe symptoms attacking persons after eating this fish are recorded.

Toadfish, or _Tetrodons_, are occasionally met with, and are to be avoided as being extremely poisonous, especially if the roe or liver be eaten. A family of coolies in Trinidad, in spite of being warned, ate one of these fishes, with a fatal result. The symptoms were blunted sensibility, trembling, general muscular weakness, difficulty of breathing, vomiting of blood, convulsions, and death.

The _Diodonts_, "trunkfishes," are not nearly so poisonous as the _Tetrodonts_, but they are found to be very noxious at certain times or in certain localities, more especially if the gall bladder, liver, and intestines are not removed before cooking. It is reported that those persons who had eaten them suffered from loss of sensibility, cold sweat over the whole body, and stiffened limbs. Death followed in some cases.

The "prickly bottle fish" (_Diodon orbicularis_), met with in the Gulf of Mexico, is said to be injurious when eaten.

The _Ostracion triqueter_, called in the West Indies "fair maid," "plate fish," "trunkfish," is often eaten with no ill effects by the negroes, who, after cleaning it, bake it in its hard shell-like covering. There is, however, a gelatinous matter near the tail which is called "the jelly," and a similar substance is found near the head. When only part of this jelly has been eaten its effects are a peculiar vertigo, nausea, vomiting, pains all over the body, more especially in the limbs. The feeling of vertigo is similar to that of intoxication, hence the fish has been called "drunken fish."

The "filefishes," or "trigger fishes," when found in the tropics, where they feed on coral polypi, have the reputation of being most unwholesome.

In the West Indies "sea eels," or murenas, are only eaten by the negroes. The blood of eels is said by Mosso to contain a poison like that of vipers. It is related that a man drank some eel's blood mixed with wine, and was in consequence seized with severe diarrhoea, disturbance of vision, foaming at the mouth, and stertorous breathing. He ultimately recovered after vigorous treatment.

Dr. Gordon, of Montego Bay, Jamaica, records a case of death from eating the flesh and liver of a species of coast conger (_Gymnothorax restratus_). In spite of treatment, the man died after a lingering illness.

Space will not permit me to dwell in this article on the remaining noxious fishes, but it is to be hoped that enough has been written to teach people to be cautious in their selection of fish when in the West Indies.

THE COLORS OF NORTHERN FLOWERS.

BY JOHN H. LOVELL.

For profusion of bloom and brilliancy of coloring, the land of the tropics, with all its luxuriance of vegetation, can offer nothing to compare with a New England meadow in June. Along the great rivers of the South or in the islands of the East strange and beautiful flowers occur individually or in small groups, but the traveler looks in vain for myriads of blossoms giving a distinctive coloring to the landscape itself. It was long the popular notion that the colors of flowers were of no importance except as they gave human pleasure. This idea has been made familiar by a well-known line of Gray's Elegy. It was a German pastor, Christian Conrad Sprengel, at the close of the last century, who first pointed out their true significance. So enthusiastically did he pursue his botanical studies that he neglected the duties of his office, and finally even omitted the Sunday sermon. The natural result followed, that he was deprived of his parish. In straitened circumstances he then sought unsuccessfully to maintain himself at Berlin by giving lessons in botany and Sunday excursions in search of plants. His book, now a botanical classic, attracted but little attention; his publisher did not even send him a copy of it, and in disgust he turned from the study of plants to that of languages. The title of the work, The Secret of Nature in the Form and Fertilization of Flowers Discovered, affords us the pleasure of knowing that he rightly estimated the importance of his observations. Sprengel clearly states that the bright hues of flowers, as is now well established, serve as signals to attract the attention of nectar-loving insects flying near by. He was led to this conclusion very fitly by the study of _Myosotis_, the "forget-me-not." He has not been forgotten. His name and theory were rescued from obscurity by Darwin; his book a few years ago was reprinted at Leipsic, and is now universally recognized, says H. Müller, as having "struck out a new path in botanical science."

A day's stroll through the fields and woodlands is sufficient to show that yellow and white blossoms are in Nature more common than red or blue. From an examination of 741 New England and Eastern species belonging to 48 families (see table) it appears that 164 are yellow, 283 white, 71 red, 136 blue and purple, and 87 green. Greenish flowers occur in 25 families, yellow in 29, white in 32, red in 16, purple and blue in 22.

_The Predominant Colors of the Flowers of Ranunculaceæ to Cornaceæ in the Northern States._

+---------+--------+--------+--------+---------+-------- | Yellow. | White. | Red. | Blue. | Green. | Total. --------------+---------+--------+--------+--------+---------+-------- Ranunculaceæ | 19 | 19 | 2 | 14 | 6 | 60 Magnoliaceæ | 1 | 4 | .. | .. | 1 | 6 Anonaceæ | .. | .. | .. | 1 | .. | 1 Menispermaceæ | .. | 2 | .. | .. | 1 | 3 Berberaceæ | 2 | 3 | .. | .. | 1 | 6 Nymphæaceæ | 3 | 2 | .. | 1 | .. | 6 Sarraceniaceæ | 1 | .. | .. | 1 | .. | 2 Papaveraceæ | 4 | 2 | 2 | .. | .. | 8 Fumariaceæ | 2 | 3 | 2 | 1 | .. | 8 Cruciferæ | 17 | 37 | 2 | 5 | 4 | 65 Capparidaceæ | .. | 1 | .. | .. | .. | 1 Resedaceæ | 1 | .. | .. | .. | .. | 1 Violaceæ | 4 | 6 | .. | 8 | .. | 18 Cistaceæ | 4 | .. | .. | .. | 4 | 8 Droseraceæ | .. | 3 | 1 | .. | .. | 4 Hyperaceæ | 18 | .. | 2 | .. | .. | 20 Elatinaceæ | .. | .. | .. | .. | 1 | 1 Caryophyllaceæ| .. | 32 | 15 | .. | 6 | 53 Portulaceæ | 1 | .. | 3 | 1 | .. | 5 Malvaceæ | 5 | 4 | 10 | 3 | .. | 22 Tiliaceæ | .. | 2 | .. | .. | .. | 2 Camilliaceæ | .. | 2 | .. | .. | .. | 2 Linaceæ | 3 | .. | .. | 1 | .. | 4 Geraniaceæ | 3 | 2 | 2 | 6 | .. | 13 Rutaceæ | .. | 2 | .. | .. | 1 | 3 Anarcardiaceæ | 1 | .. | .. | .. | 5 | 6 Vitaceæ | .. | .. | .. | .. | 7 | 7 Rhamnaceæ | .. | 3 | .. | .. | 4 | 7 Celastraceæ | .. | .. | .. | 2 | 1 | 3 Sapindaceæ | 2 | 2 | 2 | .. | 5 | 11 Polygalaceæ | 2 | 3 | 4 | 5 | .. | 14 Leguminosæ | 19 | 28 | 6 | 61 | 2 | 116 Rosaceæ | 19 | 44 | 13 | 2 | 2 | 80 Calycanthaceæ | .. | .. | .. | 3 | .. | 3 Saxifragaceæ | 2 | 20 | .. | 1 | 13 | 36 Crassulaceæ | 2 | 3 | 1 | 2 | 1 | 9 Hammelaceæ | 1 | 1 | .. | .. | 1 | 3 Halorageæ | .. | .. | .. | .. | 9 | 9 Onagraceæ | 15 | 2 | 4 | 5 | 4 | 30 Melastomaceæ | .. | .. | .. | 3 | .. | 3 Lythraceæ | .. | 1 | .. | 8 | .. | 9 Loasaceæ | 1 | .. | .. | .. | .. | 1 Cactaceæ | 3 | 1 | .. | .. | .. | 2 Cucurbitaceæ | .. | 2 | .. | .. | 1 | 3 Umbelliferæ | 8 | 33 | .. | 2 | 2 | 45 Araliaceæ | .. | 3 | .. | .. | 3 | 6 Cornaceæ | .. | 11 | .. | .. | 2 | 13 |---------+--------+--------+--------+---------+-------- Total | 164 | 283 | 71 | 136 | 87 | 741 --------------+---------+--------+--------+--------+---------+--------

Yellow appears to have been the first color developed, and flowers with this coloration are usually simple and regular in structure, as the buttercups and five-fingers. But why, it will be asked, should yellow have been the primitive color? The spores and spore-cases of the club mosses, and the pollen of all cone-bearing trees, and, in fact, of most plants, are yellow, and the yellow coloration of the first petals is doubtless correlated with this fact. Flowers of this tint are peculiarly attractive to yellow-banded flies, and when dull are avoided by beetles. Yellow flowers vary greatly in size, but pale yellow flowers are usually small, and bright or orange-yellow are large. _Ranunculus abortivus_ and _R. sceleratus_, which grow in wet places, are small and pale, while _R. bulbosus_ and _R. acris_, the familiar buttercups of our meadows, are an inch broad. An apparent exception to the above rule is offered by the globe-flower (_Trollius laxus_), found in dense swamps, which has solitary, very large, pale greenish-yellow flowers. As the cultivated European and Asiatic species have bright yellow flowers, the coloring of the sepals of _T. laxus_, for the petals are wanting, has probably retrograded from growing in dense shade.

Yellow flowers in their natural state exhibit but little variation of color. They change most readily to white, and less often to red or blue. Under cultivation sudden variations from yellow to white have been observed. A double yellow hollyhock, according to Darwin, suddenly turned one year into a single white kind, and a chrysanthemum has been seen to bear both yellow and white flowers. It will be observed in the accompanying table that in all families in which yellow flowers are common, white are also common, except in the _Hyperaceæ_, which contain no white-flowered species. Some species of mustard regularly fade to white, while many white flowers show that they are descended from ancestral yellow forms by retaining vestiges of this color on the base of the petals, as in the water-crowfoot. The pale yellow flowers of _Oenothera laciniata_, of the cultivated _Ribes aureum_, and of _Diervilla trifida_ in fading change to rose or red, exhibiting a tendency to develop red coloration. _Aquilegia canadensis_ produces scarlet flowers, which are yellow inside and rarely all over. There are two other species in the Northern flora which exhibit similar coloring, _Lonicera sempervirens_ and _Spigelia marylandica_, and the former is sometimes yellow throughout. _Myosotis_ is at first pale yellow, and changes to sky-blue. But the best illustration of the transition from yellow to blue is exhibited by the violet family; the smallest and simplest species is yellow, the most highly specialized is blue, and all the intermediate stages are presented by _Viola tricolor_.

Honey-guides are exceedingly rare among yellow flowers. _Cassia chamæcrista_, which has nearly regular, showy yellow flowers, has two or three petals with a purple spot at base, while four of the anthers are yellow and six purple. It is interesting to compare with this flower the change of color presented by _Arnebia_. When the flower opens, each lobe of the yellow corolla is marked by a dark purple spot, which soon begins to fade, and by the next day has entirely disappeared. _Saxifraga aizoides_ has golden flowers spotted with orange, and attracts a large number of insect visitors, and the yellow violets have their petals marked with dark-brown lines leading to the honey glands. Sulphur-yellow flowers are visited chiefly by bumblebees, and their coloration seems to have been developed by their selective influence from red or purple-flowered ancestors. Müller observed that the sulphur-yellow flowers of _Sempervivum Wulfenii_, which are unlike the primitive yellow of the _Crassulaceæ_, are purple at base. This purple coloring he believed to be a remnant inherited from an earlier purple-flowered form. _Hibiscus trionum_, which is sulphur-yellow with a blackish eye, has perhaps been derived from a red-flowered ancestor, for the three other species of the genus are rose or flesh colored.

White flowers, in the opinion of the writer, are due to retrogression, and are derived from yellow, red, or blue, and in some instances from the primitive green, as in the involucre of _Cornus_. As a whole they present no advance in specialization over yellow flowers, and are often smaller and less conspicuous. When the petals of blossoms containing yellow, red, or blue pigments are placed in concentrated alcohol they turn to white. To produce these pigments is evidently more or less a tax upon the energies of the plant, which, whenever possible, is avoided. They are not present in the embryonic buds, and may not develop until they are well advanced in size. In _Gentiana crinita_ the yellowish-white bud is nearly an inch long before the purple coloring appears, and the corolla always remains white at base. A stimulus to the growth of the plant makes itself apparent in the increased brilliancy of the flowers, as when they are exposed to clear sunlight or are treated with nitrate of soda, and may also be observed in the flushing of tulips, by which they lose their variegated colors when treated with strong manure. On the other hand, a check in nutrition and growth will cause a diminution of the perianth in size, accompanied by retrogression in color. When double red poppies are transplanted the whole plant is dwarfed, while the flowers are much smaller and pure white. This view of the origin of white flowers explains why they are the commonest in Nature, accounts for their being most numerous in families in which yellow flowers are likewise numerous, and why they are most true to name under cultivation. Many white flowers also exhibit other evidences of degeneration in their structure. Numerous species of _Cruciferæ_ and _Caryophyllaceæ_ have small white flowers, which regularly fertilize themselves; and in _Lepidium_, _Stellaria_, and _Sagina_ the petals are sometimes present and in other instances are wanting.

White flowers often develop red or blue coloration. It is interesting to note that the red and white varieties of the hyacinth were derived from the wild blue form earlier than the yellow. Darwin gives an instance of a white and red rose produced on the same root, also of white and pink flowers on a single plant of _Antirrhinum majus_. _Cratægus oxyacantha_, a dark pink hawthorn, has been known to throw out a tuft of pure white blossoms. Every stage of the transition from white to red is placed before us by the rose family. The thorns are white, rarely tinged with rose; in the pear and apple the flowers are white, regularly shaded with red; and one of the _Spiræas_ is rose, rarely white, while in the roses proper the six species are rose-colored, but the prairie rose changes to white. Under cultivation the wild geranium has been seen to produce upon the same plant both white and blue flowers. Good examples of the transition from white to blue and from blue to white may be met with in the _Ranunculaceæ_ and _Leguminosæ_. _Delphinium tricorne_ is bright blue, sometimes white, _Viola canadensis_ has the petals white inside but the upper ones tinged with violet beneath, _Astragalus_ has a part of the species white and a part purple, while it is common to find blue and white varieties of _Hepatica_ growing on the same grassy bank. White flowers pass more readily into red, blue, or yellow than any one of these colors can be converted into any other, since it is easier to develop a new pigment than to transform one already existing. This is confirmed by the experience of florists, who always seek to obtain a white variety from which to develop the desired hue.

Red flowers are much rarer than blue, and both are seldom common in the same family. For instance, in the pink family red and white blossoms prevail, and there are no blue shades. The pinks are crimson and scarlet, often with elegant markings and a strong aromatic odor. The honey is deeply concealed, and they are visited almost exclusively by butterflies and millers. Twenty-eight species of diurnal _Lepidoptera_ have been collected upon a single variety of _Saponaria_. Of the eighty species of _Rosaceæ_, thirteen are red and two purple, but the forty-four white flowers are very generally tinged or tipped with red. The two purplish-flowered species, _Geum rivale_ and _Potentilla palustris_, belong to genera in which yellow predominates, and this primitive color is still evident in both their calyx and corolla. There are no blue or violet flowers. This family exhibits a marked tendency both in stem, leaf, bud, flower, and fruit to develop reddish coloration, a tendency which is probably due to the chemical constitution of the sap. There are no flowers in this family adapted to _Lepidoptera_, but they are visited by a mixed company of flies, beetles, and _Hymenoptera_. The smaller and less specialized _Rosaceæ_ are yellow and white and are visited by a variety of short-lipped insects. With the increase of the flower in size and conspicuousness the number of insect visitors greatly increases, and the enlargement of the flower is attended by red coloration. Owing to the chemical constitution of the nutritive fluid, probably to its acidity (for when the petals of a rose are treated with ammonia they become blue), there has been no opportunity for the development of blue coloration by insects. With the enlargement of the perianth and the increased flow of sap, red tints have tended to appear by process of oxidation.

The correlation of red coloring with an increased flow of sap is well illustrated by the galls of the wild-rose tree, which are often "as rosy as the rosiest apple." An abnormal flow of sap is caused to the part stung by the insect, and red coloration is due to the action of light, for it is of no service to the plant. Again, when the flowers of _Cratægus coccinea_ are stung by the gall-fly the different organs all become bright red, and the change in coloring is accompanied by an increase in size. In some instances red colors, according to Darwin, indicate greater vigor on the part of the plant, and I have also observed that the dwarfing of red flowers under cultivation may cause them to revert to white.

It was long, indeed, believed that the same species could not produce yellow, red, and blue flowers. But this doctrine, to use the words of Dr. Lindley, "must now be laid up in the limbo of pleasant dreams." This supposed law is contradicted by the hyacinth, pansy, _Delphinium cardinale_, and many other plants. Though red and blue coloring never occurs among the roses, a hyacinth has been seen to produce a perfectly pink and a perfectly blue blossom on the same truss, and the _Borraginaceæ_ afford examples of flowers turning from red to blue in even a short space of time.

Blue is the highest color of the floral world, and is preferred by bees. Blue flowers are, as a rule, highly specialized both in form and color, and often possess marvelous mechanisms which aid in disseminating the pollen. This coloring is very common in the mint and pulse families, and in this district there are in the former forty-nine and in the latter sixty-one species of blue flowers. Their structure is such that few insects besides the long-tongued bees can gain access to the honey, and in some instances a single species of flower is visited by a single kind of bee, as one of the larkspurs by one of the bumblebees. While this high specialization of the flower may insure intercrossing, it is yet open to many objections, such as scarcity of proper guests, mechanical imperfections, perforation of the flowers by bees, and development of the perianth at the expense of the essential organs.

It is noteworthy that when genera occur containing three or more species they are seldom all blue or purple; one species at least, and frequently more than one, is yellow, white, or red. In _Trifolium_, _T. pratense_ is rose-purple, _T. repens_ white, and _T. agrarium_ yellow. In the genus _Astragalus_ a part of the species are violet or blue and a part white, and the same is true of _Lespedeza_ and _Vicia_; in _Lathyrus_ three species are blue-purple, one yellow, and one yellowish white. It is probably more advantageous in these genera for a part of the species to be of one color and a part of another than for all to be blue. When species are closely allied bees tend to visit them indiscriminately, as has been observed to be true of the buttercups, _Spiræas_, and golden-rods. During an afternoon the writer carefully collected the insect visitors to _Solidago bicolor_, our only cream-colored golden-rod. Both the number of species and of individuals taken was much larger than upon the yellow-flowered and more abundant varieties of this genus growing near by. There could be no doubt that the whitish coloration was beneficial in enabling insects to distinguish it more readily. Many purplish flowers are regular, often showing indications of degeneration, are devoid of honey, and are self-fertilized or adapted to _Diptera_, or, as in _Hepatica_, which is visited by bees for the pollen, open to a wide circle of visitors. In the sea purslane (_Sesuvium maritimum_), a prostrate maritime herb, there are no petals, but the five-parted calyx is purplish inside. The genus _Ammannia_ of the _Lythraceæ_ has the petals small, purplish, and in one species they are wanting; the axillary flowers of _Bracenia purpurea_ are small and dull purple; in the common papaw the lurid purple flowers are large and adapted to _Diptera_, as are probably the lurid purple flowers of _Calycanthus_. Blue flowers may revert to red, white, or yellow. The fringed _Polygala_ of Britain is usually bright blue, but often reverts to pink and white; there is a pure white variety of the blue-eyed grass; _Mertensia virginica_ is purple-blue, rarely white; the larkspur is bright blue, sometimes white, and a white variety of the purple _Trillium_ frequently occurs; there is, indeed, no improbability of a white-flowered form of every species being discovered. _Viola calcarata_ is normally blue, but sometimes changes to the ancestral yellow.