120 



COMPARATIVE MORPHOLOGY OF FUNGI 



germinate with a germ tube (Fig. 72, 4) which may develop to a myce- 

 lium or sporangiophore. 



Entomophthoreae. — In this tribe the sporangia have become conidia, 

 as in the higher Mucoraceae. Conidiobolus utriculosus, parasitic on 

 Tremellaceae, may be cultivated on artificial media (Brefeld, 1884). Its 



Fig. 72. — Basidiobolus ranarum. 1 to 3. A conidium has divided as in Fig. 70 into two 

 halves which behave as gametangia and form a zygospore each. 4. Germinating zygospore. 

 (1 to 3 X 335; 4 X 575; after Eidam, 1887.) 



conidia germinate with a single germ tube, which in insufficient nourish- 

 ment, ends in a secondary conidium, but under favorable conditions 

 develops to a mycelium with numerous sacs. This is coenocytic when 

 young; after one or two days, however, it forms numerous septa. Finally 



Yiq. 73. — Conidiobolus utriculosus. 1. Mycelium with condiophores. 2. Single coni- 

 diophore. 3. Conidiophore which has discharged its conidium. 4. Copulation of two 

 gametangia. 5. Zygospores. 6. Germination of zygospore with a conidiophore. (1 X 

 80; 2, 3, 6 X 200; 4, 5 X 150; after Brefeld.) 



it breaks up and the sacs develop to tubes, each of which grows upward, 

 swells apically and cuts off a conidium (Fig. 73, 1). The septum projects 

 convexly into the conidium. With the further development of the 

 conidium the septum is reversed into the conidiophore and is subsequently 

 differentiated into two lamellae. The conidiophore swells turgidly and 



