514 PETCH : 



the first ; and the process continues until a chain of eonidia 

 is produced. The macroconidia are therefore produced in a 

 basipetal manner and are not endogenous. (It is now genei-ally 

 admitted that this observation is incorrect.) 



Went states that the size of the macroconidia, and that 

 of the microconidia too (but in a less degree), is extremely 

 variable, so that the measurements given are only approxi- 

 mately true. Macroconidia and microconidia may be produced 

 on branches of the same mycehal filament ; and in cultures 

 started with either form, both kinds of eonidia are produced. 

 He also considers that both macro- and micro-conidia may 

 occur in the same chain, and he figures a case in which the 

 first three eonidia are macroconidia, formed basipetally, 

 while tlie fourth is a microconidium formed within the liyj^ha. 

 (But there is no doubt that this observation is incorrect, and 

 that he was mistaken in his idea of the mode of formation of 

 the macroconidia.) 



As the result of various cultures, Went concludes that the 

 fungus can invert dextrine and saccharose into glucose, can 

 make ethylic alcohol out of glucose, and finally can oxidize 

 this alcohol to acetic acid. The odour of pineapples, which it 

 causes in diseased sugar cane, is due to the formation of ethyl 

 acetate. Went observes that the odour disappears from old 

 cultures of the fungus, so that it is probable that ethyl acetate 

 may be assimilated by Thielaviopsis . 



Went's figures in the Annals of Botany are still the most 

 accurate that have been published of this species. 



Massee. 



Massee obtained his material from the West Indies, and 

 cultivated the fungus at Kew. The nutrient solution employed 

 was a decoction of sugar cane. His account is complicated 

 by the introduction of two other species, Trichospkceria 

 sacchari and Melanconium sp. He considered that the 

 Thielaviopsis and the Melanconium were stages in the Ufe 

 history of the Trichosphceria, but it is now generally admitted 

 that this view is doubtful. The Melanconium is common 

 on sugar cane in the West Indies, but the Trichosphceria is 

 apparently rare. 



