Aleae. — Pflanzenkrankheiten. 23 



*& 



the distinction between Eudorhia and Pleodorina to be but slight 

 so far as it relates to the difference in shape of the colonies and in 

 size araong the cells in the same colony. Pleodorina is an advance 

 on Eudorina in the direction of Volvox, where the distinction between 

 somaiic and reproductive cells is stronglj^ accentuated. 



Ethel S. Gepp. 



Narita, S., Notulae ad algas Japoniae. II (Journ. Bot. IV. 

 p. 212—216. London, July 1915.) 



An enumeration of about thirty marine algae, with one novelty — 

 Caulerpa Okamurai Web. f. nov. minor. He recognizes eightjapanese 

 species of Gelidium. Aniphiroa nobilis Kütz. and A. dilatata Lam. he 

 regards as forms of A. anceps. Ethel S. Gepp. 



West, G. S. and C. B. Starkey. A Contribution to the 

 Cytology and Life-History oi ZygJierna ericetorum (Kütz.) 

 Hansg., with some remarks on the genus ZygogO)iimn. 

 (The New Phytologist. XIV. p. 194-205. 5 figs. London 1915.) 



In each cell of Zygnema ericetorum there is normall)'- only one 

 large axiie chloroplast of indefinite outline. It is usualh' constricted 

 in the middle and in some cases twisted. There are two large 

 pyrenoids, one in each half of the chloroplast. The latter nsually is 

 more or less masked b}'' numerous oil-globules. A low temperature 

 causes the cell-wall to thicken, and cysts to be produced. Filaments 

 of the aquatic form grow well in a 0.2 per cent. Knop's Solution. 

 Filaments of the terrestrial form when placed in water gradually 

 fragment and become dissociated into short lengths of cells; which 

 may, however, ultimately grow into long filaments. If placed in 0.1 

 per cent. Knop's Solution, similar fragmentation occurs, but is longer 

 delayed When allowed to dry gradually, the filaments fragment 

 into thick-walled "cysts". 



The genus Zygogonium as founded b}^ Kützing (1843) is unte- 

 nable; and available evidence does not support the retention of 

 Zvgogonium on the basis put forward bv De Bary (1858) and 

 Wille (1909). " Ethel S. Gepp. 



Bailey, F. D., Powdery scab ofpotatoes in Oregon. (Science, 

 n. s. XLII. p. 424-425. Sept. 24, 1915.) 



Referring to Spongospoi'a. Trelease. 



Biodgett, F. M., Sweet pea powdery milde w. (Phytopathologv. 

 V. p. 237. Aug. 1915.) 



Microsphaera Alni, on Lathyrus. Trelease. 



Collins, J. F., The chestnut bark disease on freshlv fal- 

 len nuts. (Phytopathology. V. p. 233—235. f. 1. Aug. 1915") 



Referring to Endothia parasitica. Trelease. 



Graves, A. H., Root rot of coniferous seedlings. (Phytopa- 

 thology. V. p. 213-217. f. 1—2. Aug. 1915.) 



Ascribed to lack of oxygen in soil saturated with water. 



Trelease. 



