104 COMPARATIVE MORPHOLOGY OF FUNGI 



In all these genera, the sporangium which has become functionless, 

 remains in open connection with the sporiferous hyphae; it retains its 

 more or less definitely capitate shape and collapses only after maturity 

 of the partial sporangia. It has degenerated only in so far as the sterile 

 inner part is no longer separated from the peripheral spore protoplasm 

 by a columellar wall. In Piptocephalis it also takes part in the develop- 

 ment ; it loses its typical capitate form, and shrinks to a verrucose basal 

 cell (Fig. 63) bearing at its top the partial sporangium which is freed 



Fig. 63. — Piptocephalis Frescniana. in, mycelium with haustoria, h, which penetrate 

 the hyphae, M, of Mucor Mucedo; Z, zygospore with its two suspensors, S. Conidiophore 

 at the right. (After Brcfeld.) 



from the sporiferous hypha by its degeneration (Brefeld, 1872; Tieghem, 

 1875). The partial sporangia, as in Syncephalis aurantiaca, break up 

 into monosporous members in which the sporangial membrane is fused 

 with the spore membrane and is externally almost indistinguishable from 

 it. The sporangiophores, therefore, have been changed into conidio- 

 phores which may be recognized as original sporangiophores only by 

 their phylogeny. 



The catenulate spores of Piptocephalis, which correspond to the 

 sporangiospores of Syncephalastrum plus the section of the surrounding 



