THE SPHAEROBOLUS GUN 293 



passed uninjured through the alimentary canal of the animals 

 concerned. 



Fischer x and subsequent workers have found that the spores of 

 Sphaerobolus do not germinate readily. He tried feeding them to 

 birds and subjecting them to high temperatures, but all in vain. 

 At length he succeeded in inducing a few spores to germinate in a 

 dung-decoction. 



Pillay 2 and Miss Walker 3 both succeeded in germinating the 

 spores of Sphaerobolus by placing them in water to which a trace of 

 pepsin had been added. This is a very significant fact in connexion 

 with the dispersion of the fungus by herbivorous animals, and we 

 shall return to it again in a later Section. 



Pillay 4 observed that the germ-tube of a spore of Sphaerobolus 

 stellatus soon branches and from the first exhibits conjugate pairs of 

 nuclei and develops clamp-connexions over the septa. Thus S. 

 stellatus behaves like Hypochnus terrestris as investigated by Kniep. 5 

 Pillay's observations go to show that S. stellatus is not heterothallic 

 like most of the Higher Fungi, but is homothallic — a conclusion 

 supported by the subsequent work of Miss Walker. 6 



Miss Walker 7 observed that in the germ-tubes of the spores of 

 S. iowensis the septa are far apart and that clamp-connexions are 

 usually absent from them. However, in one instance, she clearly 

 saw a clamp-connexion at a cross-wall and therefore concluded that 

 S. iowensis " is probably homothallic." 



Pillay 8 and Miss Walker 9 observed that there is a pair of nuclei 

 in each young basidium and later only one nucleus — the fusion 

 nucleus. They further found that the fusion nucleus divides and 

 produces a number of nuclei which make their way into the spores. 

 Each spore, when ripe, contains two nuclei which, during germination, 

 as in Hypochnus terrestris, behave from the first as a conjugate pair. 10 



1 E. Fischer, " Die Entwicklungsgeschichte der Gastromyceten," Botanische 

 Zeitung, Bd. XLII, 1884, Taf. VII, Fig. 9. 



2 T. P. Pillay, loc. cit., p. 215. 3 L. B. Walker, loc. tit., p. 172. 



4 T. P. Pillay, loc. cit., p. 216. 



5 H. Kniep, " Beitrage zur Kenntnis der Hymenomyceten, I, II," Zeitschrift fur 

 Botanik, Bd. V, 1913, pp. 593-637. 



6 L. B. Walker, loc. cit., p. 172. 7 Ibid., p. 173. 



8 T. P. Pillay, loc. cit., pp. 205, 210-211, Fig. 4 c-o. 



9 L. B. Walker, loc. cit., p. 168. 10 T. P. Pillay, loc. cit., p. 216. 



