ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 95 



generations this power of adaptation grows stronger. He has proved 

 that, m the second generation, such an adapted fungus increased greatly 

 in vitality and destructive power. The new fungus race is, however, 

 less hardy, and succumbs easily to unfavourable weather conditions. 

 Lime has proved useless as a fungicide, but Eriksson thinks that carbolic 

 lime and petroleum water may prove effective remedies for the disease. 



Experiments with Heteroecius Rusts.* — M. Tranzschel records the 

 successful injection of JEcidium Jeucosptermum, from Anemone nemorosa, 

 on Sorbus Aucuparia, the uredospores of Ochrospora sorbi developed. 

 He further proved the connection of Puccinia on Polygonum amphibii, 

 with JE. sanguinolentum on Geranium ; of a Puccinia, on Carex limosa y 

 with JE. Trientalis, and of JE. coruscans, on Picea, with a species of 

 Chrysomyxa on Ledum palustre. 



Vegetative Form of Yellow Rust.f— Jakob Eriksson has revised 

 his work on Mycoplasma, and finds that the bodies which he termed 

 " corpuscles speciaux " are not the first visible form of the fungus, as they 

 belong to a later stage in its development. He finds, first of all, in the 

 cells of the leaf a granular vacuolated substance, which takes a darker 

 violet colour when fixed and stained with Flemming, and is the myco- 

 plasma. 



When the first spots of rust begin to appear, a plasmic mass is formed 

 occupying the tissue between the different sori. It spreads as mycelial 

 filaments between the cells, or it occupies the intercellular spaces ; this 

 stage he terms protomyceUum. In the third stage the protomycelium 

 becomes septate, and forms a pseudoparenchyma, and this is followed by 

 the formation of the sporiferous hymenium. 



Hetercecious Rusts. J — H.Klebahn has collected from many sources 

 all that is known about these rusts. He gives a list of the species of 

 which the life-cycle has been traced — 150 in all — and discusses the 

 different questions touching on their growth. The occurrence of the 

 different forms, the conditions that influence their growth, spore dissemi- 

 nation, infection, methods of culture, theories as to the spread of the 

 rust disease, and theories as to their sexuality, occupy the first part. 

 The second half of the book takes up each species in full detail. There 

 are complete indices and graphic tables of illustration ; the whole 

 forming a valuable summary and book of reference. 



Infection Experiments with Rusts.§ — Ernst Jordi extends still 

 further our knowledge as to the specialisation of rust forms. Under 

 Uromyces Fake he finds there are four specialised forms on the different- 

 hosts, species of Vicia., Lathy r us and Pisum. Uromyces Ervi grew only 

 on Vicia hirsuta. U. AnUnjllidis infected only AnthyJUs Vulneraria. 

 Experiments were also made with U. Hedysari obscuri and U. Astragali. 

 The latter species grows on a number of host-plants. 



* Centralbl. Bakt., xi. (1903) p. 10G. 

 t Comptes Rcudns, cxxxvii. (1903) pp. o7S-< c 0. 



% Die Wirtsweehseliulcn Ro^tpilze. (Jebr. Boi ntr'.iger, Berlin, 1903, pp. xxxvii. 

 and 447. 



§ Centralis. Bakt. x. (1933) pp. 777-9. 



