ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 649 



The uredospores of this species vary to a great extent, and are con- 

 stantly two-celled. Transition forms between the one-celled and two- 

 celled spores are also frequently found. The teleutospores have been 

 found as yet only on plants from Japan. The author rewrites the 

 diagnosis of the species. 



W. Bandi * completes his accounts of experiments with Phragmiclium 

 subcorticium and Puccinia Gar ids- Montana;,. In the first he has deter- 

 mined two biological forms, on different species of Rosa. In the sedge 

 Puccinia he finds there are also two forms that produce their teleuto- 

 spores on Carex montana ; but while one forms its gecidia on Gentaurea 

 ■montana, the alternate host of the other is Gent. Scabiosa. 



Puccinia dispersa and its adaptive Parasitism.f — H. Marshall 

 Ward discusses the persistence of the Uredospores. He found that 

 some spores germinated after sixty-one days. He records many interesting 

 observations as to the influence of temperature, light, &c, in aiding or 

 retarding germination. He has found in the course of the experiments 

 that though the uredospores from one species of Bromus will infect only 

 the closely allied species, there are yet what he terms " bridging species " 

 or intermediary species between the different groups that carry over the 

 fungns from one section of the genus to another. Tables are furnished 

 of the different experiments. 



In another communication the author % gives a detailed study of the 

 germination, infection, and growth of the mycelium of the Uredo in the 

 tissue of grasses. He deals with the behaviour of the nuclei, vacuoles, 

 septa, branches, haustoria, and other details of the hyphge up to the 

 commencement of spore-formation. Special attention was paid through- 

 out to Eriksson's mycoplasma hypothesis. Marshall Ward refutes this 

 theory ; he finds that Eriksson's corpuscles speciaux are the cut-off 

 haustoria of the fungus, and are not the outgrowths of latent germs 

 in the cell. 



Rusts of Special Natural Orders.§ — J. Ivar Lindroth has pub- 

 lished new diagnoses and a general revision of the Uredineai that are 

 parasitic on Umbelliferge. He divides the Puccinia, into the following 

 groups : — 



1. Reticulatae. The epispore of the teleutospores has a netlike 

 structure. 



2. Psorodermse. The teleutospores are covered more or less thickly 

 with warts. 



?>. Bullatae. The teleutospores are smooth, the membrane of the 

 uredospores is thickened at the apex. 



4. This group includes a number of interesting forms, the teleuto- 

 spore sori of which are a long time covered by the epidermis of the 

 host, the spores have a thickened apex and a coloured persistent stalk. 

 Only a few of the Umbelliferae rusts show these peculiarities. 



5. In the last group there are only 3 species ; the spores themselves 

 resemble those of group 5. They are all Lepto- Puccinia. 



* Hedwigia, xlii. (1903) pp. 119-52. f AnD. Mycol., i. (1903) pp. 132-51. 



X Proc. Roy. Soc, lxxi. (1903) pp. 353-4. See also Proc. Cambr. Phil. Soc, xii. 

 (1903) p. 84. 



§ Act. Soc. Faun, et Fl. Fenn., xxii. No. 1 (1902) 223 pp. (1 pi.). Meddel. 

 Stock!). Hogsk. Bnt. Inst., v. (1902). 



