12 



RESEARCHES ON FUNGI 



P. Kleinii forma sphaerospora Grove ; his P. microsporus is P. 

 crystallinus Tode ; and his P. rorichis is P. longipes van T. 



Sex in the Pilobolidae. — We still know comparatively little about 

 sex in the Pilobohdae. Van Tieghem ^ (1875) found the zygospores 

 of Pilaira anomala (Cesati) Schroter in two of his cell-cultures, in 

 one of which three spores had been sown and in the other five, while 

 Brefeld^ (1881) found about fifty zygospores of the same fungus on 



Fig. 6. — Pilobolus crystallinus. Stages in tlie formation of a zygospore. 

 A, two aerial zygophores from two different hyphae have 

 approached one another and have come into contact. B, the 

 zygophores are increasing in size and have become progametes. 

 C, the progametes have each become divided by a septum into a 

 terminal gamete c and a proximal suspensor. D, the gametes have 

 fused and have become converted into a large, thick-walled, oil- 

 bearing zygospore to which the enlarged suspensors are still 

 attached. Drawn by W. Zopf. From his Die PtVze (1890, p. 84). 

 Magnification : A, B, and C, 160 ; D, 165. 



horse dung. Zopf ^ (1888) observed the formation of the zygospores 

 of Pilobolus crystallinus (Fig. 6) and (1892) of P. Kleinii in cultures 

 in which the Piloboli were attacked by parasites * and suggested 

 that their formation was due to the action of the parasites ; but this 



1 P. van Tieghem, " Nouvelles recherches sur las Mucorinees," Ann. Sci. Nat., 

 6 ser., T. I, 1875, pp. 57-58. 

 - O. Brefeld, loc. cit., p. 65. 



3 W. Zopf, " Zur Kennt. d. Infectionskrankh. nied. Thiere u. Pflanzen," Nova 

 Acta Acad. Leop., Bd. LIT, Nr. 7, 1888, pp. 352-358, Taf. VI, Figs. 8-17 ; Beitrdge z. 

 Morph. u. Physiol, niederer Organismen, Heft II, 1892, pp. 5-10, Taf. I, Figs. 4-7. 



4 P. crystallinus and P. Kleinii were both attacked by Pkotrachelus fulgens, and 

 the former species also by an undetermined species of Syncephalis. 



