250 PETCH : THE FUNGI 



radiculosa, B. and Br., which is said to grow on the ground with 

 a long root or threads in the soil. This root is not developed 

 in the specimens at present available. Whether there is any 

 connection between the yellow mould and the Peziza has not 

 yet been ascertained. 



Mucor, Thamnidium and Aspergillus may be regarded as 

 impurities which find access to the cultivations but are not 

 present in the nest. The remaining two fungi are not easily 

 accounted for. Both can develop underground, and it cannot 

 be supposed that their spores would remain dormant in a 

 medium and situation so admirably adapted for their growth. 

 The presence of only two fungi on the combs in situ appears 

 to demand a systematic process of weeding on the part of the 

 termites. 



Even this however would not quite explain the subsequent 

 growth of these two fungi, since weeding would lead either to 

 a complete extermination or to the development of a large 

 quantity of yellow mycelium in the comb. If the yellow mould 

 is exterminated its appearance in cultures is purely acci- 

 dental ; and there is no coloured mycelium to show that it 

 vegetates in the comb material. 



It seems most probable that the foreign fungi are weeded 

 out by the termites, but that Xylaria (nigripes ?) defies 

 their efforts to exterminate it. All the other fungi which 

 develop in cultures are probably due to infection after removal 

 from the nest. It should however be recorded that neither 

 the hyphomycete nor the discomycete have been observed 

 on the hundreds of diseased parts of plants which have been 

 kept in the laboratory in the course of disease investigations. 



Entoloma Microcarpum. 

 It had been hoped to place the relation of the conidial 

 -pheres to the agaric beyond doubt by growing them from 

 (ho spores of the latter, but up to the present no germination 

 el these spores has been obtained. The agaric appears to 

 arise from the same mycelium, and the resemblanoe of the 



