ZOOLOGY AND BOTANy, MICROSCOPY, ETC. 153 



With regard to the season of infection, the above three species vary 

 to a slight extent. Climatic factors are important in spore dispersal, and 

 in affecting the condition of the host-plant. In that region the in- 

 fluence of atmospheric moisture is not a changeable condition ; there is 

 almost no variation. Heat was found to further the growth of rusts. 

 Other factors studied were the position of the ground, deep and damp 

 soils favouring the rusts, and the kinds of manure used. Tiie quantity 

 of seed sown was without influence. 



Uredinese. — W. H. Long* has established the recidial stage of 

 Coleosporlum rihkola. It was obtained by inoculating plants of Ribcs 

 Uptanthum and R. longifoUum with the fficidiospores of Perider)nium 

 from the needles of Finns edulis. The resulting uredospores on the Ril)es 

 leaves proved to be those of Coleosporlum ribicola, so that the a3cidial 

 stage should be called Peridermium-ribkoJa. 



J. R. Weir and H. E. Ernest f report a serious disease of Pinns 

 jwnderosa seedlings, due to Peridermium filamentosum, which attacked 

 the stems. The alternate form, Gronartivm coleosporioides, was found 

 in close proximity, growing in great abundance on Gastilleja miniata. 

 As the seedlings were free from traumatic injuries, the mycelium of the 

 parasite must have penetrated the epidermis of the host-plant. The 

 period of development between the penetration and the development of 

 the aecidia was about ten to eleven months. 



Paul Crucbet J has discovered and described two new UredincEe in 

 Switzerland. The first is a Uromyces on PMeum MkheJii, and by a 

 series of cultivation experiments he found the a3cidial host to be 

 Ranuncidus montanus. He points out the differences between these 

 stages and those of neighbouring species. The second Uredine was 

 found on stalks of Calluna vul/jaris. There were only uredospores, but 

 every evidence went to prove that the fungus was a Thecopsora, and was 

 named provisionally 2\ Fischeri. 



P, Dietel § discusses the systematic position of Uredo alpestris, so far 

 uncertain owing to the absence of the teleutospore form. He finds 

 that there are two types of uredospore borne in distinct sori, and there- 

 fore the affinity with Uredinopsis is strongly suggested. 



Gr. Jacob II has written an account of the Uredines of the geranium, 

 of which the ascidia gi'ow on plants of that genus, while the Fuccifiix 

 develop on Polygon um ; he makes special reference to the species 

 FucciuM Polygoni-amphdni. He discusses also the species of Uromyces 

 Puccinki on geranium. 



J. S. BrycelF publishes a note on the pycnidia of Gronartium 

 pyriforme, which lie has observed for the first time. They occurred on 



* Mycologia, viii. (1916) pp. 309-11. 



t Journ. Agric. Research, v. No. 17 (1916) pp. 781-5. See also Bull. Agric. 

 Intell. Rome, vii. (1916) pp. 759-01. 



t Bull. Soc. Vaud., li. (1916) pp. 73-9 (4 figs.). 



§ Ann. Mycol., xiv. (1916) pp. 98-9. See also Bot. Centralbl., cxxxi. (1910) 

 p. 654. 



II Centralbl. Bakt., xlvi. (1915) pp. 617-58. See also Bot. Centralbl., cxxxii. 

 ,(1916) pp. 33-4. 



If Phytopathology, vi. (1916) pp. 446-7. 



