80 
DESCRIPTION." 
The principal general features of this fungus as it appears 
when fully developed on insects infested by it are its pure white 
color,—a little* tinged with brown or yellowish when oldest,—the 
thick, soft felt with which it covers the surface, often completed 
ly enclosing the smaller insects, and especially the multitude of 
minute spherical heads (about .06 mm. in diameter) visible with 
an ordinary hand lens. When picked apart under the micro¬ 
scope, myriads of minute spherical or slightly oval spores 1.5- 
2.5 in diameter are disengaged, and the heads are then seen 
to be composed of masses of such spores borne upon radiating) 
threads, all springing from the end of a short lateral branch of 
the thread-like mycelium. More minutely studied, these spores 
are seen to be placed in an alternating manner upon the 
radial filaments, so that when they are detached the naked 
filament has a slightly zigzag form. If traced to its precise 
origin, each zigzag filament (rachis) is found to start in a large 
obovate spore-like cell, and to bear a spore at its very tip. 
Where a young head is forming at the end of a spur or from 
some point on a thread, a few larger oval bodies will be seen 
attached to a common point, and prolonged at their apices 
into a short, slender tube with a spherical enlargement (often 
minute) at its tip. As this terminal swelling becomes a spore, 
the stem grows past it, leaving it lateral in position although 
terminal in development. The mycelium itself, forming the 
greater part of the felty mass, is a closely interwoven web of 
delicate filaments, averaging 1.5—3 ^ in thickness, segmented at 
rather long intervals, much branched and occasionally anasto¬ 
mosing. In an artificial culture on a solid medium the growing- 
mass comes finally to have the appearance of a thick, piled-up 
layer of very fine foam or lather, yellowing slightly as the spores 
become ripe.t 
*The following is a translation of the description of genus and species given by Saecardc 
in his “Sylloge Fungorum,” vol iv (1886), pp. 96 and 101: 
Sporotrichum Link. Sp. pi. Fungi I, p. 1, em. Sacc. Mich. II, p. lb.—Hyphen irregular!' 
and repeatedly branched, septate or continuous, usually procumbent, uniform. Comdi; 
ovoid or subglobose, commonly sub-solitary, acrogenous at the apices of branches or den 
tides. Differs from Botrytis especially by the sub-solitary conidia, and the entirely pro¬ 
cumbent hyph.se; from Trichosporium in that the color is never black. 
Sporotrichum globuliferum Speg. Fung. Argent. Pug. II, p. 42. Tufts rather large,1. 
mm. in diameter, external or internal, white, cottony-floecose; hyphrn creeping, sparseb 
septate, hyaline, 3-4 micros thick, densely branched and anastomosing. Cornelia minute 
globose or globose-elliptical, hyaline, 2-2.5 by 1.5-2 micros, collected in globose heads 60-7< 
micros in diameter, which are thickly scattered among the hyphse. 
+ The following description of this fungus from a recent culture on agar has been fur 
nished me by Professor T. J. Burrili. since the aboye was written: 
Agar cultures three days old. Growth forming an irregular fleecy, white, loose stratun 
on the nutrient surface. Under a lens some parts, evidently of the oldest, show a granuia 
appearance from the presence of heads of spores; other parts are evidently still barren. 
Sterile mycelium slender, uniform in size, about 2.5 micros, septate at considerable in 
tervals and often branched, the branches usually starting just below a septum and growing 
out somewhat at right angles to the main thread. Sometimes the filaments are long an< 
straggling, sometimes bushy-branched. in the latter case the branches apparently mor 
common as the fungus becomes older. Anastomosis frequent. 
The spores are. borne in globular heads on the ends of certain branches of the myce 
lium. These latter seem to be irregularly produced, but in most cases when fruiting i- 
normally abundant they arise near each other as short lateral projections of somewna 
