284 



Transactions British Mycological Society. 



Series A. Commenced Dec. 9th. Conidia from sources shown. 



One inoculation in each experiment. 



No. of Source of 



Expt. conidia 



A I. Swede 



A 2. Brussels Sprout 



(subinfection) 

 A3. Swede 

 A 4. Brussels Sprout 



A 5. Swede 



A 6. Brussels Sprout 



A 7. Swede 



A 8. Brussels Sprout 



A 9. Swede 



A 10. Brussels Sprout 

 All. Swede 



Outer surface ditto. — 



B. Sprout petiole — 



epidermis removed 



Full 

 infection 

 M.S.K. petiole, epi- Full 

 dermis removed infection 



A 16. Swede 



A 17. Brussels Sprout 



A 18. Swede 



B. Sprout petiole 

 small piece of epi- 

 dermis removed 



'Cut B. 

 petiole" 



Sprout 



infection 



Full 

 infection 



Full 

 infection 



Full 

 infection 



Overrun by mould 



Conidia germinated 

 but overrun with 

 mould 



Strong mycelium and 

 many conidia by 

 Dec. 17th 



Strong mycelium by 

 Dec. 17th 

 Both showed strong 

 mycelium and many 



i conidia Dec. 15th. 

 Both showed a dis- 

 colouration of the 

 host cells 



Slight myceUum 

 Dec. 17th then died 

 out 



Strong mycelium 

 with many conidia 

 by Dec. 15th. Later 



"■i spread to uninjured 

 surface where it dis- 



\ coloured the cells 



Strong mycelium and 

 many conidia Dec. 

 17th but died by 

 Jan. 6th 



Very weak mycelium 

 Dec. 17th then died 

 out 



Strong growth with 

 conidia Dec. 17th. 

 Later spread to and 

 discoloured the cells 

 of uninjured surface 



Spread without dis- 

 colouration 



Spread on to unin- 

 jured surface with- 

 out discolouration 



Spread without dis- 

 colouration to un- 

 injured surface 



