258 



THE LOWER FUNGI— PHYCOMYCETES 



on the work of van Tieghem and le Monnier (1873: pZ. 23, jig. 63), 

 who figure germination stages in C. jonesii. They show the 

 rupture of the spiny wall (sporangia! wall) and the escape of a 

 smooth-walled spore. Brefeld (1881: pi. 2, fig. 1) made the 

 same observation. Preceding rupture the two walls are in close 

 contact and indistinguishable. The homology of the conidium 



Fig. 91. — (a-c) Chaetocladium brefeldii van TicKhem & le Monnier. (d) 

 Ch. jonesii Fresenius. (a) Portion of branching thallus showing conidia, sterile 

 branchlets, and a zygospore. (6) Germinating conidium producing threads 

 which are attacking a hypha of Mucor sp. (c) A cluster of short branches 

 surrounding the host hypha in connection with haustorium formation, (d) 

 Germinating conidium. (After Brrfcld 1872, 1891.) 



of this genus with the sporangium of other members of the order 

 would have been clear, of course, even in the absence of a 

 visable double-walled condition. 



Choanephoraceae 



Sporangium present in some forms, absent in others; either 

 sporangiola or conidia present in all cases, and covering terminal 

 capitate enlargements of branches of the sporangiophore or 

 conidiophore. 



