1900 } DEVELOPMENT OF TRICHURUS AND STYSANUS 315 
in together that they form a thick mat. None of the vegetative 
hyphae grow above the agar, so that the colony never presents 
a flocculent appearance. 
If at this time one of the colonies is lifted out of the agar 
and examined under the microscope, its surface will be found to 
be dotted with small peculiar sporophores, resembling very 
much the conidial fructification of Penicillium, or still more, 
perhaps, on account of the slight coloration of the spores, the 
form genus Haplographium (figs. 6, 7). These gonidiophores 
show great variability. Those first formed consist of a single 
erect hypha bearing a chain of gonidia at its summit. Others 
have three or four branches, each with a chain of gonidia. In 
the older parts of the mycelium, toward the center of the colony, 
these small gonidiophores become more and more complex (jig. 
7). Their branches divide and subdivide until it is impossible 
to represent them. In some of the gonidiophores a sterile branch 
takes the place of a basidium (fig. 7), and later, when the 
colony is a little older, all the gonidiophores bear long-curved 
setae, many times longer than the entire fruiting head, so that it 
sometimes seems as if a small stalk had spent all its effort in 
producing one of these enormous curved setae. 
In these sterile threads, intermingled with the chains of 
gonidia, one sees a resemblance between the Penicillium form 
and the perfect sporophores. In time, still greater similarity 
appears. The heads formed near the center of the colony begin 
to assume a different appearance. The stalks are considerably 
elongated, and become brown and septate before the head of 
gonidia is formed (figs. 8, 9). Often two or three grow near 
together, forming a distinct stipe like that of the perfect sporo- 
phore in every respect except size. The stalk hyphae do not 
remain simple, but send out branches from their lower cells. 
These branches grow upward and soon attain a diameter equal 
to that of the stalk. The manner of origin of these branches 
can be seen best in the more simple sporophores. They pei 
usually sent out from the lower cells, always originating 1mme- 
diately below a septum ( figs. 9, roa). Fig. 8 shows a small 
