118 



COMPARATIVE MORPHOLOGY OF FUNGI 



1897; Lowenthal, 1903; Woycicki, 1904, 1907, 1927; Olive, 1907; Lakon, 

 1926; and Levisohn, 1927), and B. myxophilus on bacterial zoogloea on 

 fallen pine needles (R. E. Fries, 1899). 



The mycelium of B. ranarum develops abundantly on the excrement 

 of frogs in 2 to 3 days. It consists of ramose hyphae whose cells when 

 young are uninucleate and sometimes, in age or poor nourishment, multi- 

 nucleate. The hyphae are persistent in the excrement, but in artificial 

 culture may break up into oidia, resembling the hyphal bodies of the 

 Entomophthoraae. 



After a short time, asexual reproduction begins. Each cell grows into 

 a thin, upright sporangiophore, which projects above the medium, swells 

 clavately at its end and absorbs the nucleus and considerable cytoplasm 



Fig. 70. — Basidiobolus ranarum. 1. Young mycelium with conidiophores. 2. Conid- 

 ium germinating as conidiophore. 3. Conidium. 4. Conidium which has divided once, 

 each half germinating with germ tubes. 5 to 8. Development of conidium and its appara- 

 tus of discharge. (1 X 40; 2 X 140; 3, 4 X 375; 5 to 8 X 335; after Eidam, 1887.) 



from the cell (Fig. 70, 5 to 8). The swelling is abjointed as a sporangium. 

 Although only a thin protoplasmic peripheral layer remains in the 

 sporangiophore, the absorption of water from the mycelium continues 

 uninterruptedly. When the increasing turgidity exceeds the elasticity 

 of the membrane, the sporangiophore splits, and its dome, together with 

 the sporangium, flies off a few centimeters. While still in the air, the 

 portion of the sporangiophore usually falls off the sporangium. The 

 discharged sporangium is pyriform and papillate below (Fig. 70, 3). On 

 the papilla there is a small hyaline peg with triangular base and a 

 small tip with a fine point where the sporangium separated from the 

 sporangiophore . 



The sporangia are eaten by beetles, principally Carabidae, Scarabaei- 

 dae and Silphidae which prowl about the excrement. These in turn 

 furnish food for the frogs. In the intestinal tract of the frog, the nucleus 



