Thomas H. Macbride

“ 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. ”

“ If an author recognized and defined a given species in times past, and, in accordance with views then held, assigned the species to a particular genus, common honesty, it would seem, would require that his work be recognized. ”

“ The possession of walls is an indication of some maturity. In the slime-mould the assumption of walls is indeed delayed. Walls at length appear and when they do come they are like those of the lily; they are cellulose. The myxomycetes may be regarded as a section of the organic world in which the forces of heredity are at a maximum whatever those forces may be. Slime-moulds have in smallest degree responded to the stimulus of environment. They have, it is true, escaped the sea, the fresh waters in part, and become adapted to habitation on dry land, but nothing more. ”

“ May we not rather believe that life's tree may have risen at first in hundreds of tentative trunks of which two have become in the progress of the ages so far dominant as to entirely obscure less progressive types? The Myxomycetes are independent; all that we may attempt is to assert their near kinship with one or other of life's great branches.
The cellulose of the slime-mould looks toward the world of plants. The aerial fructification and stipitate habit of the higher forms tends in the same direction. ”

“ In reading Fries the modern student hardly knows which most to admire, the author's far-reaching, patient research, the singular acumen of his taxonomic instinct, the graceful exactness of the Latin in which his conclusions are expressed, or the delicate courtesy with which he touches the work even the most primitive, of those his predecessors or contemporaries. ”

“ Later, students of the specimens preserved by Mr. Phillips, concur that we have to do not with a diderma, but with a craterium, Lister, or physarum, Massee. There seems no reason why we should not respect the decision of Massee, whose description is here quoted in form somewhat abridged. The peridium is about as double as in the many physarums, not more so; the inner membrane so delicate as only occasionally to be revealed except to scrutiny most searching. But the appearance as a whole is as of some brown diderma; only the calcareous capillitium abides to prevent mistaken reference. ”

“ Aside from the injurious tendencies, possible or real, of the forms mentioned, I know not that all other slime-moulds of all the world, taken all together, affect in any slightest measure the hap or fortune of man or nation. And yet, if in the economic relations of things, man's intellectual life is to be considered, then surely come the uncertain myxos, with their fascinating problems proffered still in forms of unapproachable delicacy and beauty, not without inspiration. ”

“ The peridium may be double, varies in texture, color, persistence, and so forth, as will be more fully set forth in the several specific descriptions. The peridium blends with the hypothallus below when such structure is recognizable, either directly, when the sporangium is sessile, or by the intervention of a stipe. The stipe may be hollow, may contain coloring matter of some sort, or may even contain peculiar spore-like cells or spores; is often furrowed, and in some cases shows a disposition to unite or blend with the stalks of neighboring sporangia. ”

“ Perhaps the most striking characteristic of the present species, aside from its large size, is the peculiarly perforated cup or calyculus. Schrader's artist failed him here completely. The structure is exceedingly delicate, the peridium between the ribs and reticulations reduced to the last degree of tenuity, with the iridescence of the soap-bubble, here and there lapsed entirely. Withal the structure seems firm enough and persists until all the spores are dissipated by the wind. ”

“ A very well marked species, easily recognized, at least when stipitate, by its remarkable discoid or lenticular sporangia. After the spore-dispersal, the stipes are long-persistent, surmounted by a peculiar disk representing the consolidated columella, lower sporangial wall, and expanded stem-top. Sessile specimens are like similar forms of D. reticulatum, but in all the gatherings before us the stipitate type is at hand to reveal the identity of the species. ”

“ The material we have, however, is poor, badly weathered.
The general plan of structure corresponds very well with Fries' idea of his genus Tilmadoche, although the present species would seem, by very grossness, strangely out of place with the tilmadoches. But the singular, didermoid, evenly branching, threads of the capillitium, bearing their slender spindle-shaped burdens of lime are very suggestive; it is a diderma gone wandering into the camp of the physarums if one may judge from Miss Lister's graphic plate. ”

“ In any locality the plasmodia pass rapidly to fruit, but not infrequently a plasmodium in June will be succeeded in the same place by others of the same species, on and on, until the cold of approaching winter checks all vital phenomena. The process of fruiting should be watched as far as possible, and for herbarium material, allowed to pass to perfection in the field.
Specimens collected should be placed immediately in boxes in such a way as to suffer no injury in transport; beautiful material is often ruined by lack of care on the part of the collector. ”

“ The entire life-history of every form is none too much if we would set out with any hope of accuracy the genetic relationships for which taxonomy stands. Recently European students are making the color of the plasmodium a basis for species-discrimination, which is good so far. ”

“ To assume that any later writer who may choose to set to familiar genera limits unknown before shall thereby be empowered to write all species so displaced his own, as if, forsooth, now for the first time in the history of science published or described, is not only absolutely and inexcusably misleading, but actually increases by just so much the amount of débris with which the taxonomy of the subject is already cumbered. ”

“ In capillitial differentiation the badhamias are definite and beautiful. The net in a typical species, as B. papaveracea, is throughout uniformly evenly tubular, the calcareous deposits delicate in the extreme, presenting, as the spores disappear, an elegant trabecular structure as if to support the persisting peridium if not the original content. In other forms the capillitium is physaroid, with swollen nodes, but heavily calcareous but not quite throughout. Badhamia, Physarum, Tilmadoche, Craterium present a consistent group, of which Physarum is the generalized expression. ”

“ The shadowy little species has had an eventful history, dipping in and out of our story in most uncertain fashion. Beginning with Fries, as noted, it received confirmation at the hands of DeBary, and by Rostafinski was given priority over a long list of synonyms, and figured. The earlier English authors follow Rostafinski, but for Lister in the Mycetozoa, p. 51, the species becomes a synonym of T. alba as P. nutans, the description appropriately enlarged to receive it. ”

“ The capillitium is in some specimens particularly, of the Physarum type; in others, like that of Badhamia. There are accordingly species that receive at the hands of different authors diverse generic reference as one feature or another in the structure is emphasized in the different cases. It is granted that it is hard to draw the line sometimes between forms in which the dehiscence is irregularly circumscissile and those in which the wall breaks without any regularity whatever, since, in all, the breaking up of the peridium usually begins at the top. ”

“ Nature reverts, we say, to her most ancient and simple phases, and heredity is still consonant with apparent simplicity; apparent we say, for as becomes increasingly evident, nothing that lives is simple! ”

“ Physiologically, the fungi are incapable of independent existence, being destitute of chlorophyl. In this respect the slime-moulds are like the fungi; they are nearly all saprophytes and absolutely destitute of chlorophyl. Unfortunately this physiological character is identically that one which the fungi share with the whole animal world, so that the startling inquiry instantly rises, are the slime-moulds plants at all? Are they not animals? Do not their amœboid spores and plasmodia ally them at once to the amœba and his congeners, to all the monad, rhizopodal world? ”

“ Badhamia Rostafinski, Monograph, p. 139.
Sporangia simple; peridial wall simple, thin, breaking irregularly; capillitium formed of abundant, richly anastomosing tubules, filled throughout their entire length with calcareous granules; the nodes often feebly represented; stipe poorly developed or wanting entirely; columella, except in forms sometimes assigned to the sub-genus Scyphium, poorly developed or none; spores frequently adherent in clusters.
The whole genus calls for careful and protracted study; and the present so-called species are like something new on the world ”

“ A very variable species in many particulars. The sporangia in the same cluster are stipitate and sessile, ovoid and spherical. Our description does not quite agree with that of Rostafinski. As may be seen from the plate, it is the outer peridium that is with us white, burdened with lime, the inner is simpler and comparatively thin. The whiteness of the outer peridium is however, easily displaced. The colony may not show it at all, in which case the peridia remaining give to the fructification entire a pale lead color, very characteristic. ”

“ When newly formed, the sporangia have a peculiar rosy or flesh-colored metallic tint, which is all their own. Within a short time this color passes, and most of the material comes from the field brownish or ochraceous in color. Typical sporangia are spherical on distinct short stipes; when crowded, the shape is of course less definite. The capillitium never expands as in Arcyria, but, exposed by the vanishing upper wall, remains a spherical mass resting upon the shallow cup-like base of the peridium. ”

“ The substance of the plasmodium has about the consistency of the white of an egg; is slippery to the touch, tasteless, and odorless. Plasmodia vary in color in different species and at different times in the same species. The prevailing color is yellow, but may be brown, orange, red, ruby-red, violet, in fact any tint, even green. Young plasmodia in certain species are colorless (as in Diderma floriforme) , while many have a peculiar écru-white or creamy tint difficult to define. ”

“ The total life of an organism in any case must be taken into account. [11] At the outset plants and animals are alike; there is no doubt about it; they differ in the course of their life-histories. The plasmodium is the vegetative phase of the slime-mould. It needs no cell-walls of cellulose, no more than do the dividing cells of a lily-endosperm; both are nourished by organic food and resort to walls only as conditions change. ”

“ Berkeley's idea of the genus was expressed as follows: "Peridium naked or furfuraceous. Spores in groups, enclosed, at first, in a hyaline sack." Rostafinski, while accepting Berkeley's generic name, redefined it, emphasized the calcareous capillitium, and made reference to the spore-adherence only to assert that Berkeley's description was, in this particular, based on mistaken observation. In some species, the spores do, in fact, show a tendency to cling together, a characteristic which Badham was perhaps first to notice ”

“ This is our most common North American species. It occurs everywhere on decaying wood, sometimes in remarkable quantity, thousands of sporangia at a time. The plasmodium, watery white in [Pg 182] color, infests preferably very rotten logs of Quercus, on which in June the sporangia rise as white or pallid columns. The peridium is exceedingly delicate, less seldom seen here than in some other species, but likely to be overlooked entirely. The spores when fresh have a distinct violet or bluish tinge; in old specimens they are almost colorless. ”

“ Thus it may simply form a flat, cake-like mass, aethalium, internally divided into an indefinite number of ill-defined spore cases, sporangia; or the plasmodium may take the form of a simple net, plasmodiocarp, whose cords stand out like swollen veins, whose meshes vary both in form and size; or more commonly the whole protoplasmic mass breaks up into little spheroidal heaps which may be sessile directly on the substratum, or may be lifted on tiny stems, stipitate, which may rest in turn upon a common sheet-like film, or more or less continuous net, spreading beneath them all, the hypothallus. ”

“ To Professor Torrend, formerly of Lisbon, the writer is indebted for a set of European types, and to Professor Bethel, pathologist of Denver, for rich material from the fertile mountains of Colorado and California. To Professor Morton Peck, of Oregon, we are indebted for many notes of the color of plasmodia and for collections of Pacific coast forms. Mr. Bilgram, of Philadelphia, read the manuscript of the genus Physarum and has contributed many rare species. To Dr. Sturgis, of Massachusetts, we are indebted for material from both east and west. ”

“ At all events our American specimens correspond so well with the description of L. columbinum (Pers.) Rost. that there seems no doubt that we have here what the Polish author figured and described, whether or not he was always consistent in applying his labels. The color distinguishes at sight the present species from L. physaroides, and the capillitium and large rough brown spores distinguish it from L. violaceum. The capillitium of the minute L. scintillans is much denser and more rigid, and the spores smaller. The stipe when dry is ciliate. ”

“ Sporangia crowded, generally in dense colonies, globose, smooth, ochraceous-white, stipitate, the peridium thick, cartilaginous, splitting from above into several petal-like lobes, which become speedily reflexed exposing the swarthy spore-mass, the inner peridium not discoverable, inseparable; stipe concolorous, about equal to the sporangium; hypothallus, generally well developed, but thin, membranaceous, common to all the sporangia; columella prominent, globose or cylindric, often constricted below, and prolonged upward almost to the top of the spore-case ”

“ Slime-moulds have long attracted the attention of the student of nature. For nearly two hundred years they find place more or less definite in botanical literature. Micheli, 1729, figures a number of them, some so accurately that the identity of the species is hardly to be questioned. Other early writers are Buxbaum and Dillenius. But the great names before Rostafinski are Schrader, Persoon, and Fries. ”

“ Again it is said that the differences are in external form or color only, the spores in all cases almost if not quite the same. This is true; but specific characters are surface characters in fact: a species morphologically is merely the form in which a kind or genus presents itself. If the presentation be constant, for our convenience we say so, in bestowing a name. Whether in our present treatment the convenience is purely personal, students may decide.
However it all may be, there are in this part of the world many varying presentations of Fuligo capable of illustration and description ”

“ This remarkable species, while not at all difficult of recognition to one familiar with its phases, is withal very difficult to define. Normally stipitate, it often shows from the same plasmodium all sorts of forms, the shape of the fructification dependent apparently upon external conditions prevalent at the time. The amount of calcium also varies, especially in the capillitium, where there is usually much, with a tendency to the formation of something like a pseudo-columella; the outer net in such cases nearly destitute. The calcium in the stipe also varies ”

“ In the older species the capillitial branches fray out, and are only sparingly united into a net extremely lax. In the present form the net is the thing, common to all sporangia. The total effect is to lend to the blown-out æthalium a woolly appearance, entirely unlike that of its congener under the same conditions. But until fructification is quite mature, the presence of the collaborating sporangia below is indicated, suggested, by the papillose upper surface. ”

“ Sporangia sessile, gregarious, flattened, hemispherical; peridia simple, opening by a lid; dehiscence circumscissile, the upper part chestnut brown, the lower almost black; capillitium feebly developed, smooth, attached to the lid and usually coming away with it, bringing the brilliantly yellow spore-mass, and leaving a delicate, shining cupule adherent to the substratum; spores yellow, nearly smooth, 10–12 μ. On and under the bark of dead elms of various species. [Pg 244]
A very handsome little species occuring rarely with us, or perhaps overlooked by virtue of its protective coloration. ”