Tropical nature, and other essays

Land of the Sun! where joyous green-robed Spring And leaf-crowned Summer deck the Earth for ever; No Winter stern their sweet embrace to sever And numb to silence every living t...

_Influence of the Heat of the Soil._--It is well known that at a very moderate depth the soil maintains a uniform temperature during the twenty-four hours; while at a greater de...

In fine weather the air appears to be somewhat more transparent near the equator than with us, and the intensity of sunlight is usually very great up to the moment when the sola...

_Uses of Equatorial Forest-trees._--Amid this immense variety of trees, the natives have found out such as are best adapted to certain purposes. The wood of some is light and so...

_Orchids._--These interesting plants, so well known from the ardour with which they are cultivated on account of their beautiful and singular flowers, are pre-eminently tropical...

Although, as has been shown elsewhere, it may be doubted whether light directly produces floral colour, there can be no doubt that it is essential to the growth of vegetation an...

The great majority of butterflies disappear at night, resting concealed amid foliage, or on sticks or trunks, or in such places as harmonise with their colours and markings; but...

The Phasmidæ are perfectly inoffensive leaf-eating insects of very varied forms; some being broad and leaf-like, while others are long and cylindrical so as to resemble sticks,...

_Trogons, Barbets, and Toucans._--Many of the families of Picariæ are confined to the tropical forests, and are remarkable for their varied and beautiful colouring. Such are the...

_Bats._--Almost the only other order of mammals that is specially and largely developed in the tropical zone is that of the Chiroptera or bats; which becomes suddenly much less...

The Rufous Flame-bearer, an exquisite species found on the west coast of North America, is thus described by Mr. Nuttall:--“When engaged in collecting its accustomed sweets, in...

We may now follow the two sexes to the remoter island, at a period when the male had acquired his permanent style of colouring, but was not quite so large as he subsequently bec...

might seem to throw some doubt on the sufficiency of the explanation, the answer was easy,--that in the progress of discovery, man would, sooner or later, find out and enjoy eve...

_Protective Colours._--The nature of the two first groups, Protective and Warning colours, has been so fully detailed and illustrated in my chapter on “Mimicry and other Protect...

_Colour a Normal Product of Organization._--This outline sketch of the nature of colour in the animal world, however imperfect, will at least serve to show us how numerous and v...

_Selection by Females not a Cause of Colour._--To conscious sexual selection, that is, the actual choice by the females of the more brilliantly-coloured males, I believe very li...

_Colour-development as Illustrated by Humming-birds._--Of the mode of action of the general principles of colour-development among animals, we have an excellent example in the h...

The smaller plants whose seeds simply drop upon the ground, as in the grasses, sedges, composites, umbelliferæ, &c., always have dry and obscurely-coloured capsules and small br...

The perception of colour seems, to the present writer, the most wonderful and the most mysterious of our sensations. Its extreme diversities and exquisite beauties seem out of p...

Any help to a comprehension of the causes which may have concurred in bringing about so much diversity and beauty must be of value; and this is my excuse for laying before you t...

In Mr. Pickering’s valuable work on the “Geographical Distribution of Animals and Plants” (founded on his researches during the United States exploring expedition), he gives a l...

The antiquity of the races thus discovered cannot be measured in years; but it may be approximately determined by the successively earlier and earlier stages of civilization thr...

The animal mounds are of comparatively less importance for our present purpose, as they imply a somewhat lower grade of advancement; but the sepulchral and sacrificial mounds ex...

If we compare the productions of different islands, we meet with peculiarities which throw much light on the subject of distribution. In the Galapagos islands, between 500 and 6...

We have, therefore, good evidence that the great Euro-Asiatic continent of Miocene times exhibited in its fauna a combination of all the main features which now characterise the...

Further south, in Bolivia, the Pampas, and Patagonia, we also find abundant fossil remains, probably a little older than the cave fauna of Brazil, and usually referred to the ne...

Colours, classification of organic, 172 protective, 172 warning, 174 sexual, 177 typical, 179 of animals, how produced, 184 theory of protective, 187 theory of warning, 189 theo...