CHAPTER V. — COMPARATIVE REVIEW. — MUCORINI. 



l 53 



turn in a hair-point ; the lateral branches of the last order swell into irregularly capitate 

 basidia, from the short slender sterigmata of which 8-20 spherical spores are 

 simultaneously abjointed. Similar sporiferous structures with hair-points are formed on 

 the terminal ramifications of copiously branched gonidiophores, which rise in a curve 

 into the air from well-fed mycelia in a similar manner to the stolons of Rhizopus. 

 Many variations occur in the number and disposition of the whorls and the successive 

 orders of branches ; a small cluster of spores may take the place of the terminal 

 hair-points, especially in weakly specimens. It is hardly possible to detect any strict 

 rule in the primary branching of the stolons, the typical form of which appears to be 

 indiscriminately sympodial and monopodial. Some of the primary branches terminate 

 in spore-clusters ; others seize on 

 sporangiophores of Mucor and adhere 

 to them, and send out new stolons 

 from the points of adherence which 

 are swollen. Zygospores also are 

 formed on the stolons. Cunning- 

 ham's Choanephora may also be- 

 long to this division, with a creeping 

 endophytic mycelium and straight 

 erect simple sporophores ending in 

 umbellately arranged heads of ba- 

 sidia, from which many spores are 

 simultaneously abjointed. 



3. PlPTOCEPHALIDEAE. Ill Syn- 



cephalis the very delicate mycelium 

 gives rise to short erect unicellular 

 usually unbranched gonidiophores 

 with a circle of rhizoids at their base, 

 and with one bifurcation in S. furcata. 

 A dense umbel of simple or dicho- 

 tomously branching spore-rows is 

 formed at the capitate swollen apex 

 of the gonidiophore by the cross-sep- 

 tation of cylindrical mother-cells (see 

 section XVI). Piptoeephalis (Fig. 

 74) differs from Syncephalis in its re- 

 peatedly dichotomouslybranchedand 

 septate simple sporophores which 

 are often large and tall, and in the 

 circumstance that the capitate sum- 

 mit which bears the spore-rows falls 

 off with them when they are ripe. 

 The mycelium of the species of both 

 genera is parasitic on the larger 

 Mucoreae, making its way into their 

 cells by means of delicate haustoria 

 (section V). 



The formation of the gonidia of Chaetocladium and the Piptocephalideae was 

 described and named above in section XVI in accordance with the facts observed 

 in Chaetocladium, Piptoeephalis Freseniana, and Syncephalis. Van Tieghem's view 

 of the process is different from mine. He considers that the spore-chain of Synce- 

 phalis and Piptoeephalis is formed, like the gonidia of Mucor, simply by division of the 

 protoplasm of the mother-cell, and is then set at liberty by the disappearance (resorp- 

 tion) of its membrane ; and he regards the acrogenously formed spores of Chaetocladium 



Fig. 74. Piptoeephalis Freseniana. M piece of a mycelial tube of 

 Mucor Mucedo ; ?« mycelium of Piptoeephalis with haustoria h applied 

 to M and sending slender filaments into it, c gonidiophore, Z zygo- 

 spore on the two suspensors ss. After Brefeld from Sachs' Lehrbuch. 

 c magn. 300, the other figures 630 times. 



