200 RESEARCHES ON FUNGI 



to the group itself and to the two genera Pilobolus and Pilaira 

 included within it more precise definitions than have yet appeared. 



PILOBOLIDAE 



A family of the Mucoraceae having a sporangium which contains 

 a mass of dense jelly around its base between the sporangium-wall 

 and the spore-mass. At maturity the mass of jelly swells up and 

 causes the sporangium to dehisce near its base, so that the jelly 

 protrudes between the sporangium- wall and the columella. The 

 sporangium-wall is usually intensely black and is persistent when 

 immersed in water. 



Pilobolus Tode, in Schrift. d. Berl. Gesell. naturf. Fr., vol. v, 

 p. 46 (1784). 



Fruit-body consisting of a sporangiophore and a sporangium. 

 Sporangiophore seated on a main mycehal hypha, from which it is 

 separated by one or two septa. From below upwards, it is composed 

 of a basal swelUng or trophocyst, a cyhndrical stipe, and a more or 

 less ovoid subsporangial swelling, and when young it is generally 

 ornamented by beads of moisture. Sporangium usually jet-black, 

 seated on the apex of the subsporangial swelUng, separated from it 

 by a columella, and having its wall highly cutinised and persistent 

 when immersed in water. When mature the sporangium and 

 columella are violently projected. The species usually occur on 

 the dung of herbivorous animals. 



A. Sporangium black when mature ; no apophysis. 



1. P. crystalUnus. 5. P. sphaerosporus. 



2. P. longipes. 6. P. heterosporus. 



3. P. roridus. 7. P. oedipus. 



4. P. Kleinii 8. P. umbonatus. 



B. Sporangium yellow when projected ; provided with an apophysis. 

 9. P. nanus. 



All these species have been adequately described and figured, 

 and (whether they are truly distinct from one another or not) may 



