340 



FUNGI 



of the zygosperm has a smooth surface, not entering the external warts 

 of the extine. Azygosperms have not been observed. The sporophores 

 terminate in a fine hair-point, but below this give rise to a whorl of 

 branches nearly at right angles to each other, terminating again each in 

 a hair-point. These again branch more or less in like fashion. The 

 ultimate branches become swollen, and on these swellings fine short 

 sterigmata arise, each sterigma bearing a spore. The mass of spores 

 thus produced has a bunch-like aspect. 



Cunningham's Choanephora, found by him on the flowers of Hibiscus, 

 appears to approach most nearly to Chaetocladium. 



Sub-order 3 : PIPTOCEPHALIDE^E. This very small group (Piptoce- 

 phalis, de By., Syncephalis, Van Tiegh.) is, like the last, composed of 

 parasites on the Mucoreae, and to this end the mycelial hyphae bear 



haustoria, each of which 

 emits from its slightly 

 swollen base a small 

 crop of short delicate 

 rhizoids traversing the 

 Mucor-hypha affected. 

 The conjugating hyphas 

 of Piptocephalis are 

 arched somewhat like an 

 inverted D, the point 

 of contact being the 

 summit. Actual conju- 

 gation occurs, as in the 



FIG. 295. Piptocephalis Freseniana de By. and Wor. Con- 

 jugation and formation of a zygosperm, z. Stages in the 

 (After ~ 



order of the numbers ( x 650). (l 



Brefeld.) 



Mucoreae ; but when this 

 stage is reached, the pro- 

 duct of the conjugation 



begins to swell at the point of union, and generally on the convex 

 side, into a globular body, which becomes echinulate as it swells. 

 When it has attained its full size and development at the expense of 

 the protoplasm of the united gametes, it becomes separated from them 

 by transverse partition, and remains seated, as it were, on the summit 

 of the arch. Though not the morphological equivalent of the zygo- 

 sperm of the Mucoreae, but rather the offspring of the original zygo- 

 sperm produced by the conjugation of the gametes, it will be most 

 convenient to regard it as the zygosperm. The sporophores bear at 

 their apices series or chains of spores produced by transverse partition. 

 In Piptocephalis the sporophore is dichotomously branched at the 

 summit, and each bifurcation bears a capitulum of chains of spores. 

 Accessory acrospores are sometimes produced by Syncephalis. 



