ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 611 



Sclerotium bataticola s^^.n., once believed to be a stage of SjJhseronema 

 fimhr latum, but proved by the author to be a separate organism. 

 Another form of black rot is caused by one of the imperfect fungi, 

 Lasiodiplodia tuhericoJa. The infected tissue of the potato is jet ])lack. 

 The disease was introduced into the United States from Java. 



M. T. Cook and A. Schwarze * publish some notes on the growth 

 and development of a root-disease of dahlias caused by Botrytis, mor- 

 phologically similar to B. cinerea. The infections were always througli 

 wounds. The spores grew and germinated on various media. The 

 holdfasts developed into sclerotia. 



L. Petri f has described the effects produced by the fungus Sphse- 

 ropsis Ellisii var. Abietis on the extremities of the branches of Fseudo- 

 tsuga Douglasii. The host grew in the shade in a very moist situation. 

 Trees with a better illumination a short distance away were not infected. 

 Petri found that the mycelium had developed in the cortical parenchyma 

 and in the phloem ; it did not penetrate the xylem. 



Two species of Rhizoctonia have been described J for the Board of 

 Agriculture, i^. vioJacea and R. Solani. The former is a troublesome 

 disease of beets and carrots, in which it enters the fleshy roots and kills 

 them ; of lucerne and clover, in which it destroys the rootlets, and of 

 potatoes, in which it attacks the tubers. The fungus lives in the soil ; 

 it covers the plant attacked with a coating of mycelium, and forms 

 sclerotia which act as resting bodies. The second species, R. Solani^ 

 attacks potatoes ; it forms sclerotia connected together by almost in- 

 visible strands of mycelium. Remedies are suggested for these diseases. 



Another disease § that attacks the leaves of apples has also been 

 studied. The fungus Sphseropsis malonmi, known as apple-leaf spot, 

 may also attack the branches and trunk of the tree. In the latter case 

 it may girdle the tree and cause the death of the part above the diseased 

 area. It also causes a brown rot of the fruit. The appearance and 

 development of the fungus are described and remedies suggested. It 

 has only recently been reported for this country. 



Yincenzo Rivera || has contributed a paper on the Oidium of the 

 oak. He finds that completely developed leaves are not attacked. Young 

 leaves in a fairly humid atmosphere in which turgescence is active and 

 not subject to changes are not attacked, though the conidia germinate 

 easily on these leaves. A rise of temperature which causes a loss of 

 turgescence in the leaves is an important condition of infection. Other 

 biological notes are added. 



0. Mengel 1[ has similarly described the development of the mildew 

 of the vine and the changes induced by the environment. He considers 

 these changes under three aspects ; general, secondary, and accidental. 

 Under general causes he includes climatic disturbances. Under secondary 

 and accidental he discusses the dissemination of spores, their germination, 

 and the methods of sprinkling and fumigating. 



* Phytopath., iii. (1913) pp. 171-4 (IpL). 

 t Ann. Mycol., xl. (1913) pp. 278-80 (3 figs.). 

 : Journ. Board. Agric, xx. (1913) pp. 416-19 (1 pi.). 

 § Journ Board Agric, xx. (1914) pp 513-15 (1 pi.), 

 li Atti Reale Accad. Lincei, cccx. (1913) pp. 168-78. 

 % Comptes Rendus, clvii. (1913) pp. 292-4. 



2 S 2 



