ii. Elaters with scattered rings; sometimes

faint spirals 3. _O. nitens_

B. Spores warted 4. _O. fulvum_

1. OLIGONEMA FLAVIDUM (_Peck_) _Mass._

1874. _Perichaena flavida_ Peck, _Rep. N. Y. Mus._, p. 76. 1892. _Oligonema flavidum_ (Peck) Mass., _Mon._, p. 171.

Sporangia crowded and superimposed, sessile in small masses or clusters 1 cm. or less, bright yellow, shining, the peridium thin but opaque, yellow; capillitium of long, slender tubules usually simple, anon branched, even, or with an occasional inflation, the sculpture confined to warts or small, distinct spinules, roughening more or less conspicuously the entire surface, the apices generally obtuse, anon apiculate; spore-mass yellow, spores under the lens pale yellow, irregularly globose, beautifully reticulate, the meshes large and few, as in _Trichia favoginea_, 12-14 mu.

This species is marked by its capillitium, which is abundant for the present genus. The threads are longer than in any other species, and not infrequently branched, smooth, or more commonly, very distinctly minutely spinulose throughout, no trace of rings or relief sculpture of any sort, the spirals, that are to be expected, very imperfect, if discernible at all. In habit the species resembles _O. nitens_, but the colonies are much larger, and the sporangia higher and larger, attaining 1 mm.

New England to Iowa and Nebraska; south to Alabama and Louisiana. Toronto; _Miss Currie._

2. OLIGONEMA BREVIFILUM _Peck._

PLATE XX., Figs. 5, 5 _a_.

1878. _Oligonema brevifila_ Peck, _Rep. N. Y, Mus._, p. 42.

Sporangia small, cylindric, dull ochraceous-yellow, sessile closely crowded, sometimes superimposed, forming large, effused patches several centimetres in extent; capillitium exceedingly scant, consisting of nothing more than a few minute threads, very short, only three or four times the diameter of the spore, smooth, or without any definable sculpture, ochraceous; spore-mass dark ochraceous, under the lens the spores are brighter, marked with reticulations much as in other species of the genus, 10-12 mu.

Probably a variety of our No. 1, but constantly collected.

Separate, however, from the following also in color and habit. To the naked eye the fructification suggests _Trichia persimilis_; the color much the same, and the sporangia similarly congested. The peculiarly rudimentary condition of the capillitium is apparently also constant. Iowa specimens accord perfectly with those from New York.

Rare. New York, Ohio, Pennsylvania, North Carolina, Iowa, Missouri, Oregon, Washington, California; Vancouver Island.

3. OLIGONEMA NITENS (_Lib._) _Rost._

PLATE II., Figs. 8, 8 _a_, 8 _b_.

1834. _Trichia nitens_ Lib. _Pl. Cr. Ard._, III., No. 227. 1875. _Oligonema nitens_ (Lib.) Rost., _Mon._, p. 291. 1883. _Trichia pusilla_ Schroet., _Kr. Fl. Schl._, III., p. 114.

Sporangia gathered in small, heaped clusters, irregularly spherical, bright straw-color, or yellow, sessile, superimposed, the peridium thin, smooth, shining; capillitium of short elaters, simple or branched, smooth, adorned with an occasional projecting ring, often with faint spiral sculpture spreading especially toward the apices, which are blunt or anon acute, the point sometimes flexed or bent to one side, never very long; spore-mass bright yellow, spores globose, beautifully reticulate, 12-14 mu.

Readily recognized at sight by its heaped, shining, or glistening sporangia. The capillitial threads are further definitive, and serve to distinguish it from everything else.

The range is wide, probably coextensive with the forests of the country. Specimens are before us from New England, Canada, Montana, and all intervening regions, and south to the Gulf of Mexico; California, Nevada,--_Prof. Bethel._ Yosemite, shores of Mirror Lake!

4. OLIGONEMA FULVUM _Morgan._

1893. _Oligonema fulvum_ Morgan, _Jour. Cin. Soc._, p. 42.

Sporangia large, sub-globose, sessile, or crowded, more or less regular; the peridium tawny yellow, or olivaceous, very thin and fragile, iridescent; mass of capillitium and spores tawny-yellow, elaters simple or sometimes branched, very short, sometimes with thicker swollen portions, the surface marked with low smooth spirals, in places faint and obsolete, the extremities rounded and obtuse, usually with a minute apiculus; spores globose, minutely warted, 10-13 mu.

This species may be recognized by its tawny, irregular, more or less crowded sporangia. Under the lens the warted, not reticulate, spores are diagnostic. The elaters are quite constantly marked by imperfect spirals.

Our specimens are from the author of the species, and so far there are none reported from outside Ohio.

FOOTNOTES:

[15] For other crucifers, see _Bull. Torr. Bot. Club_, xxi, pp. 76-8.

[16] See in reference to this whole matter, _Myxomycetenstudien_ by E. Jahn, No. 7, _Ceratiomyxa_, 1908. See also Olive, _Trans. Wis. Acad. of Sci. Arts and Letters_, Vol. xv, pl. II, p. 771.

[17] See Jahn, _Myxomyceten Studien_ No. 8, Berlin 1911.

[18] In discussing these species the reader may be referred to Professor Harper's study of cytology, _Bot. Gazette_, vol. XXX., p. 217. It is probable that in all these aethalioid forms the effect of disturbance, transfer to laboratory, is likely to be quite pronounced. Giant spores are often seen, doubtless due to arrested cleavage in the procedure described by Dr. Harper: a giant spore is penultimate or antepenultimate in series; should, on this theory, occasionally, at least, show more than one nucleus.

[19] Prior to Persoon the physarums were variously referred: _Lycoperdon_, _Sphaerocarpus_, _Trichia_, etc. It seems unnecessary to quote the synonymy further here.

[20] Persoon's first-named species is _P. aureum_; see _Roemer Neu. Mag. f. d. Bot._, I., p. 88. 1794.

[21] Fries (_Sum. Veg. Scand._, p. 454) described the new genus in the following words: Tilmadoche. Fr. Physari spec. S. M. Peridium simplex, tenerrimum (_Angioridii_) irregulariter rumpens. Capillitium intertexto-compactum, a peridio solutum liberum, sporisque inspersis fuscis. Columella o.

1. T. leucophaea. Fr.

2. T. soluta. (Schum.)

3. T. cernua. (Schum.)

[22] See also _Inaug. Diss._, H. Roenn, _Schr. d. Naturw. Ver. f. Schl. Holst._, XV., Hpt. I., p. 55, 1911.

[23] Inasmuch as there has been decided difference of opinion in reference to this particular species,--all judges readers of the same original description,--it has seemed wise to submit an English translation from the celebrated _Monograph loc. cit._

"24. Physarum diderma _Rfski._

"Sporangia sessile, globose, adnate by a narrow base, white. Peridium double; the outer thick, strongly calcareous, very distinctly set off from the thin inner one by an air-filled space; the calcareous nodules many, angular, loosely developed within to form a pseudo-columella; spores dark violet, spinescent, 9.2-10 in diameter.

"_Opis._ This physarum looks extremely like a diderma.

"The sporangia stand either aggregated or bunched together in heaps of five to twelve, adnate to the hypothallus by a narrow base, etc."

Massee, _Mon._, p. 304, translated this description, but misunderstood what is said of the columella and is inclined to think the author did not know a diderma when he saw one; which is pretentious, to say the least!

[24] See also, after all our trouble, _Jour. Bot._, LVII., p. 106.

[25] See Fries, _Syst. Myc._, Vol. III., pp. 130, 137, Rost., _Mon._, p. 127, and _Rep. N. Y. State Mus._, XXXI., p. 55.

[26] It would seem that M. Massee would have written _T. reniformis_, were this authentic.

[27] For further synonymy, see under _P. auriscalpium_, No. 49.

[28] Robt. E. Fries, _Ofvers. K. Vetens. Akad. Forh._, 1899, No. 3, p. 225.

[29] The Polish author wrote Tilmadoche instead of Physarum in each case cited.

[30] Forms cited are chiefly those likely to be found in our neighboring tropics, West Indies, etc.

[31] These little structures have a fairly architectural appearance and may be called trabecules,--trabeculae, little beams.

[32] Dr. Cooke, who used the microscope, applied the _Monograph_ description to British forms occurring on leaves; proceeded further and found the same situation in New York. Mr. Massee gives the species wide range with spores 8-10 mu; average 9 mu; only a fraction too large; evidently none 12-15 mu.

[33] If a sporangium of _L. tigrinum_ be mounted in water and treated to weak solution of hydro-chloric acid we may easily discover that the crystals, which so wonderfully adorn the outer wall in this and other species, consist, in part at least, of calcium carbonate. We may also discover that in the case before us the crystal or scale lies indeed enclosed in a filmy sac of organic origin, and that could we have seen the outer peridium as it came to form, we might probably have found it made up largely of an ectosarcous foam in whose cavities the excreted calcium found place for tabulate crystallization. In other species listed, conditions are different, and the crystals assume a different shape. The phrase "bicarbonate of lime" quoted in this connection in the former edition of this work from Mr. Massee's _Monograph_, etc., is not clear.

[34] Doubtless immature; _v. Mitteil. Naturwiss. Gesell. Wintert._, VI., p. 64, Lister quoted by Schinz.

[35] Vid. _Mycologia_, N. Y., Vol. IX., p. 328.

[36] See _Addenda, d_, p. 282 following.

[37] In the _Mycetozoa_, 2nd ed., p. 158, is cited _Stemonitis virginiensis_ Rex as a synonym of this variety. By reference to p. 163 of the present volume the Virginian stemonitis is left as Rex assigned it, and if the present variety be synonymous, it should be quoted there. The treatment of the species _C. nigra_ in the second edition does not establish such fact, nor with three varieties make for any increasing clearness.

[38] It had seemed less necessary to retain the classic orthography in this instance since De Bary and Rostafinski both use _Diachea_. But modern scholarship is nothing if not meticulous; it is the fashion in Latin still to keep the digraph, even to the vexation of all men. In the same way when Bulliard wrote _leucopodia_, 'white stockings', he doubtless meant to be exact.

[39] For this citation we are indebted to _Mr. Hugo Bilgram_.

ADDENDA

a. This volume is as we see, a descriptive list of the various forms of the Myxomycetes in so far as these have come to the personal notice of the writer.

Each form is designated, as is usual in discussing objects of the sort, by a particular binomial name, followed, in abbreviated form, by the name of the student or author who in describing the form in question used the combination. Thus _Stemonitis splendens_ was first described by Rostafinski, and the name he thus used is applicable to the form he described, wherever found, and to _nothing else_.

The proper naming of any specimen would thus appear to be a very simple matter. Such, however, is often not the case, particularly where we are concerned with species long familiar to science. Such often have received, at different times, and at the hands of the same author, or certainly of different authors, different names, given for various reasons; so that one who would refer to, or discuss, a single specimen to-day finds himself often in great uncertainty, confronted by a multitude of binomial combinations all thought to refer to the same particular thing.

By general consent, of course, we strive to ascertain the oldest name on the list; the first that is really and clearly applicable, and we write all other names down as synonyms. In this volume a list of synonyms often accompanies the description; precedes it, showing, year by year, the history of the case; an abstract in fact of the title, as at last approved. The preparation of such an abstract is very troublesome, but is believed to be worth the trouble; must be made, indeed, if we are ever in our discussions to be sure that when we speak or write in America, we are dealing with the same thing intended by the man who speaks or writes in England, or elsewhere.

The space occupied in synonymy, is therefore by no means wasted. By and by, if we succeed in establishing a nomenclature on which competent judges can agree, a thing not at all improbable, almost now attained, the lists may gradually disappear as having historical value only.

b. Taxonomy, in any field, is of necessity concerned with history. For his own sake, no student can ignore the thought and work of his predecessors. No man ever sees nature in completeness, nor even the small part of the world to which he devotes attention. He needs every possible assistance, especially the observations of intelligent men. The present author rejoices to acknowledge the assistance found in volumes written in Europe during the last two hundred years. Such men as Persoon, Bulliard, Schumacher, Schrader, Fries, are deservedly famous; they laid the foundations of mycologic taxonomy. No student can afford to miss _Elias Fries_; his genius, spirit and scholarship entitle him to the recognition and sympathy of every lover of the intellectual life.