Fault .— The Cytology of the Laboulbeniales. 651 
The compound antheridia of three genera were examined— Dichomyces , 
Dimorphomyces , and Enarthromyces. The nucleation observed was seen to 
differ in no way from that of the simple antheridia. The nature of the 
common chamber into which the efferent passages of the individual 
antheridia open was not determined. But an examination of specimens 
of Enarthromyces kindly loaned me by Professor Thaxter seems to show 
that they are, in this form at least, modified cells. It is possible, too, that 
the compound antheridium has originated quite independently more than 
once in the course of the evolution of the forms bearing simple antheridia, 
and in different ways, that is, on the presumption that the latter is the more 
primitive type. 
The Procarp. 
The procarp of several genera has been examined, but that of Dioicho- 
myces , Amorphomyces , Stigmatomyces , and Laboulbenia has received most 
careful attention. There are many difficulties attendant on the elucidation 
of the nuclear phenomena, so that except in the case of Laboulbenia chaeto - 
phora I am not yet in a position to state with sufficient positiveness the 
origin of the pair of nuclei found eventually in the carpogenic cell. 
The procarp has its beginnings as a single uninucleate cell, an out¬ 
growth from the receptacle. It develops into a structure that consists of 
three parts—a uninucleate carpogenic cell, a uninucleate trichophoric cell, 
and a trichogyne. The trichogyne, as in Stigmatomyces , is unicellular and 
uninucleate, or, as in several species of Laboulbenia , is a more or less highly 
branched and septated organ. About the time the carpogonium becomes 
binucleate the trichogyne withers, and then the trichophoric cell begins to 
degenerate. I have seen spermatia attached to trichogynes, but, as yet, 
have not been able to demonstrate their entrance into or fusion with them, 
possibly on account of the dense stain taken by the receptive cells of the 
trichogyne at this stage. Nor have I been able to detect a nucleus migrating 
down through the trichophoric cell. 
The carpogenic cell does acquire a second nucleus, and the ascogenic 
cells, too, in all the genera that have come under observation, are binucleate. 
In some forms the intermediate stages have been followed more or less 
completely, showing that the binucleate condition is maintained. I have seen 
no evidence of a nuclear fusion in the carpogenic cell or ascogonium, though 
the possibility of the occurrence of such a fusion is not precluded. 
As for Laboulbenia chaetophora , it is possible to give a practically 
complete account of its developmental sequence. This species, like its 
near relative L. Gyrinidarum , is interesting because of the lack of antheridia, 
or of any organs that might function as antheridia. The trichophoric and 
carpogenic cells are uninucleate at the outset. The nucleus of the latter 
very soon divides, and one daughter passes to the lower end of the cell, 
