ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 585 



fungus Avintered in the rosette leaves of the plant ; mycelium was 

 found in these leaves though only in limited areas, and uredospores 

 produced from the mycelium in spring serve as the source of renewed 

 infection. 



J. E. Weir and E. E. Hubert* record successful inoculations of 

 Larix occidental is and L. europsea with Melcmqjsora Bigelowii. The 

 teleutospores were applied in April, and spermogonia and ascidia 

 appeared in the following May. Abies lasiocarpa was successfully 

 infected with Pucciniastrum pustiihitum, collected from the leaves of 

 EpiJobium a ngtist /folium. 



Dry-rot.t — Percy Groom gives an account of ^lerulitis lacrymans, 

 which causes dry-rot of timber. After attacking the wood, it sends 

 down into the tissues fine hypha^ which feed on tht; wo )d-substance, 

 and it also gives forth superficial hyphee which form into strands, sheets, 

 or cushion-like growths, which send down further hyphte into the 

 wood. Spore-bearing tissues are superficial, but in the immersed 

 mycelium " gemmae " and oidia may also be formed. Methods of 

 dealing with the fungus are described. 



Cultures of Rhizoctonia crocorum.f — As the disease associated 

 with the fungus is increasing in America, W. H. Diehl has devoted 

 some time to a study of the fungus in artificial cultures. He found 

 that the fungus was of very slow growth. The best results were 

 obtained on " radicicola " agar, which contains water, saccharose, dipo- 

 tassium phosphate and agar-agar in definite quantities, but, even on this 

 medium, very poor growths were obtained, and these were not found to 

 be capable of infecting healthy alfalfa roots. 



Horse-hair Blights. §—T. Fetch gives a description of these hair-like 

 structures, fine rhizomorphic strands of mycelia which spread freely over 

 bushes and trees at some height from the ground. So far as is known, 

 all these black threads belong to some species of Marasmius ; the 

 common species in the Eastern tropics being Afnrasmius eguicrinis, and 

 in the West Indies 31. sarmentosus. The mycelium is purely epiphytic, 

 and adheres to the leaves and branches of the trees by thin disks of fine 

 brown hypha?. These anchoring hyphte may rise from any part of the 

 rhizomorph, but their formation seems to depend on the supply of 

 moisture. 



Fetch has described several other Ceylon species of Marasmius, and a 

 new Aylaria, X. vac/ans, which grows on leaves. 



Pseudo-sclerotia of Lentinus similis, etc.|l — An account of the 

 development of these sclerotia is given by T. Fetch. The mycelium of 

 the fungus permeates the wood on which it grows, filling all the 

 elements of the wood or the spaces, and forms with the wood a solid 



* Phytopathology, vi. (1916) pp. 372-3. 



t Journ. Board Agric, xxiii. (1916) pp. 465-74 (12 figs.). 



X Phytopathology, vi. (1916) pp. 836-40. 



§ Ann. Roy. Bot. Gard. Peradeuiya, vi. (1915) pp. 1-26 (6 pis.). 



y Ann. Roy. Bot. Gard. Peradeniya, vi. (1915) 18 pp. (1 pi.). 



Dec. 30th, 1916 2 s 



