ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 225 



North California caused by Macrophoma Fici which has been recorded 

 from Africa. It causes cankers on the larger branches, and fruits 

 inoculated 'with the spores were destroyed by development of the fungus. 

 The pycnidia grew well in cultures ; the great variation in the size and 

 shape of the spores is noted. 



A disease of Squashes, due to Choanephora cucurbitarum, has been 

 studied by F. A. Wolf.* It causes a blight of the flowers and a rot of 

 the fruit, considerable loss having resulted from its presence. It is the 

 only known species of the genus recorded in America, and a full account 

 of the fungus is given. Sporangial, chlamydosporic and zygosporic 

 stages were developed in artificial cultures. 



A new strain of Rhizoctonia Solan i and its effects on potato .tubers 

 forms the subject of a paper by J. Rosenbaum.f He claims that the 

 different strains can be distinguished with accuracy in macroscopic 

 growth on various media as well as by morphological comparisons. 

 Strain R5, the new fungus, is more pathogenic on the stems and produces 

 a distinct necrosis of the tubers. Differences were found in the size, 

 etc., of the sclerotia and of the hyphal cells. 



A Rhizoctonia potato disease has also been examined and described 

 by G. B. Ramsey. I It attacks the tubers and seems to have been con- 

 fused with potato-scab. The tubers are attacked through the lenticels, 

 and the scab formed may penetrate to the core of the tuber, or, in 

 another phase, the shrinkage of the tissues causes the formation of a 

 pit or canal, frequently suggesting wire-worm injury. 



A needle-blight of Douglas fir has been described by J. R. Weir § 

 which has caused great damage in forest and nursery. The needles 

 affected develop spots in early winter of a slightly yellow colour on the 

 under surface. The infected needles fall at all seasons of the year, and 

 the trees may become entirely defoliated. The fungus is as yet unde- 

 scribed, but seems to be a member of the Stictidaceie. Spraying with 

 soap and Bordeaux mixture is recommended. 



F.I). Fromme and H. E. Thomas |1 describe a Xylaria root-rot of 

 apple-trees that is becoming a serious menace in the chief orchard 

 sections of Virginia. It is marked by l)lack encrustations on the surface 

 of the roots, with dark zonations in the internal bark and wood. The 

 progress of the fungus (A'. Hypoxylon) is comparatively slow, but two 

 years of infection may produce the death of the tree. 



A new leaf -spot on turnip has been reported in various localities in 

 Georgia and has been identified by B. B. Higgins IT as due to Colleto- 

 trichum Brassicse, or to a new species, C'- Higginscanum Sacc. Inocula- 

 tion experiments were made on seed-pods with the results indicated that 

 though the pods were infected and many seeds destroyed, the fungus 

 was not carried over in the seed. 



A nursery blight of Cedars {Juniperus, Thvja and Cupressus) has 



* Journ. Agric. Research., viii. (1917) pp. 319-27 (2 pis.). 



t Journ. Agric. Research, ix. (1917) pp. 405-19 (2 pis.). 



X Journ. Agric. Research, ix. (1917) pp. 421-6 (4 pis.). 



§ Journ. Agric. Research, x. (1917) pp. 99-103 (1 pi. and 3 figs.). 



ll Journ. Agric. Research, x. (1917) pp. 163-73 (2 pis. and 1 fig.). 



\ Journ. Agric. Research, x. (1917) pp. 157-61 (2 pis.). 



