1914] THAXTER—NEW ZYGOMYCETES 359 



sporangial spores, comparing them to the phaeophragmic spores of 

 Thielavia basicola, in which the endospore may become more or 

 less separable from the exospore before the disunion of the spore- 

 segments. To the writer such an explanation seems highly improb- 

 able, nor does the presence of the Oedoce phalum type in diverse 

 and scattered instances among the higher fungi seem in the least 

 significant in this connection; but rather as an indication that this 

 simple and effective method of economizing space and raising a 

 large number of spores above the substratum is a convenient 

 type, which has been used independently by various unrelated 

 groups, even by the Peronosporales. 



The spores of Syncephalastrum appear to arise by internal, not 

 always transverse, cleavage, rather than by transverse septation as 

 in the phragmospores of Thielavia basicola, and the bodies which 

 contain them are in the writer's opinion true sporangiola, from which 

 it is a very short step to the "conidia" of Cunninghamella, which, 

 as has been suggested, might be regarded as monosporic sporangiola. 

 That monosporic sporangia are not an anomaly in the Mucorales is 

 shown by the characters of the genus described below as Haplo- 

 sporangium. This opinion seems further substantiated by the 

 comparison already made between Choanephora and the present 

 genus, the sporangiola of which are, as has been pointed out, but a 

 short step from the "conidia" of the former, and are clearly shown 

 • to be sporangial in their nature, not only through the presence of 

 intermediate forms, but by reason of their peculiar appendages so 

 characteristic of sporangiospores in the Choanephorae. 



In a majority of the other " Cephalideae " the conditions are 

 superficially, though not fundamentally, different from those seen 

 in Syncephalastrum, owing to a different arrangement for spore- 

 dissemination. An intersporal substance is here present which 

 causes the sporangiospores to cohere at first, and to separate only 

 when this substance together with the sporangium wall becomes 

 transformed to a somewhat viscous fluid; which, as in species of 

 Syncephalis, causes all the spores formed on a given head to become 

 united in a large viscous droplet, which adheres to small Drosophili- 

 dae and other insects frequenting the substrata on which th y 

 grow. In Syncephalastrum, on the other hand , the spore-mass when 



