120 Transactions British Mycological Society. 



Fig. 



10. Two conidiophores of H. Solani from a 30-day old culture 



on a sterilised potato stalk. The one on the right 

 shows the "collar" at its apex, that on the left is in 

 process of developing a fresh conidium. x 340. 



11. Germinating chlamydospore of H. Solani. x 560. 



12. Conidiophore of Langloisula macrospora. x 340. 



13. Germinating conidium of L. macrospora. x 340. 



Plate IV, 



1. Portion of the mycelium produced from a single ascospore 



(seen in the centre) of Hypomyces Solani in four days on 

 a wort-gelatine cover-glass film, x 200. 



2. An 8-day old individual of H. Solani, developed from a 



single ascospore on a wort-gelatine. The very numerous 

 globules of conidia can just be seen with the naked eye 

 as black dots, x 10, 



3. Portion of the individual shown in Fig. 2, showing the 



conidiophores with their terminal globules of conidia. 



4. A culture of H. Solani on oat extract agar, eleven days old. 



The first six days' growth occupies the centre and is 

 more or less blurred by the presence of the large numbers 

 of conidia-globules, many of which have fused together. 

 The growth during the subsequent five days is clearly 

 zoned. The lighter circles consist of aerial conidio- 

 phores, bearing conidia-globules; the darker, wider 

 bands consist of more or less submerged mycelium. 

 A dark and a light band, forming one zone, developed 

 each 24 hours, the light circle of conidiophores being 

 produced last and during the night, x i|. 



5. Groups of chlamydospores of Verticillium nuhilum from 



a pure culture on oat extract agar, x 360. 



6. Chlamydospores of V. nigrescens from a pure culture on 



oat extract agar. The mycehum which bore these 

 spores is now practically invisible, x 310. 



