ZYGOMYCETES. 



99 





period of rest, producing a new hypha, which bears a sporangium 

 (Fig. 81 JS). 



Mucor mucedo, Pin- 

 mould, resembles some- 

 what in appearance 

 Penicillium crustaceum 

 and is found growing 

 upon various organic 

 materials (bread, jam, 

 dung, etc.). 



Pilobolus (Figs. 83, 

 84) grows on manure. 

 Its sporangium (Fig. 84 

 a") is formed during the 

 night and by a peculiar 

 mechanism (page 92) is 

 shot away from the plant 

 in the course of the day. 

 This generally takes 

 place in the summer, 

 between eight and ten 

 a.m. The sporangium 

 is shot away to a height 

 which may be 300 times 

 greater than that of the 

 plant itself, and by its 

 stickiness it becomes 

 attached to portions of 

 plants, etc., which are 

 in the vicinity. If these 

 are eaten by animals, 

 the spores pass into the 

 alimentary canal and 

 are later on, sometimes 

 even in a germinating 

 condition, passed out 

 with the excrement, in 

 which they form new 

 mycelia. 



Phycomyces nitens 

 (" Oil-mould ") is the 

 largest of the Mould Fungi ; its sporangiophores may attain the height of 10-30 c. m. 



Order 2. Rhizopaceae. Ehizopus nigricans (Mucor stolonifer) which lives 

 on decaying fruits containing sugar, on bread, etc., has, at the base of the 

 sporangiophores, tufts of rhizoids, i e. hyphae, which function as organs of 

 attachment. From these, " runners " are produced which in a similar manner 

 develope sporangiophores and rhizoids. 



Order 3. Thamnidiaceae. On the same sporangiophore, in addition to a 



FIGS. 81, 82. afucor mucedo: A-C stapes in the formation of 

 the zygote ; D zygote ; E germination of zygote : the exospore 

 has burst, and the endospore grown into a bypha bearing 

 a sporangium. 



