FERMENTATION BACTERIOLOGY. 337 



single spore. In the heterothallic group, which embraces a large majority of the 

 species, the zygospores are developed from branches which belong to mycelia of 

 diverse character and can never be obtained from the Bowing of a single spore. 



Therefore, every heterothallic species is an aggregate of 2 distinct strains, and the 

 sexual strains show generally a more or less marked differentiation in vegetative 

 luxuriance, which is designated by the author for convenience by the use of the plus 

 and minus signs. The development of these different strains and their relation to 

 each other are discussed at considerable length. 



Summarizing the observations, the author concludes that the formation of zygo- 

 spores is a sexual process; that the mycelium of a homothallic species is bisexual, 

 and of a heterothallic species unisexual, and that the plus and minus series of a 

 heterothallic group represent the 2 sexes. A considerable bibliography of this sub- 

 ject concludes the contribution. 



The anatomy of leaves of British grasses, L. Lewton-Bkain ( Tnn>,<. Linn. Sue. 

 Bot. [London], 2. ser., 6 {1904), X". 7, pp. 315-359, pis. 5; abs. in Bui. ( 'entbl.,95 ( 1904), 

 No. 25, p. 659). — The object of this paper is to present by means of diagrams and 

 descriptions of the transverse section of the leaf, material for the identification of 

 grasses from their vegetative characters. The first part of the paper gives an account 

 of the general anatomy and histology of the grass leaf, dealing in particular with the 

 general outline of its transverse section, structure of epidermis, the mesophyll, vascu- 

 lar bundles, etc. In the second part of the contribution about 80 species of grasses 

 are arranged according to an artificial key based upon the anatomical structures men- 

 tioned in the preceding part, while the third part of the paper discusses the leaf 

 structure of the different grasses in relation to their habitat. 



The influence of oxygen on chlorophyll production, J. Fkiedel [Bui. Sue. 

 Ilnl. France, 51 (1904), No. 2, pp. 100-103). — In continuation of experiments on the 

 effect of atmospheric pressure on chlorophyll production (E. S. R., 14, p. 653), the 

 author has given the results of additional experiments with other plants which tend 

 to confirm his previous conclusions. All the plants experimented with were grown 

 under conditions in which the atmospheric pressure could be regulated and compari- 

 sons drawn between their growth in rarefied air, in atmospheres of oxygen of varying 

 pressures, and under normal conditions. It was found that chlorophyll production is 

 dependent upon the absolute amount of oxygen present and is independent of the 

 total pressure of the gas. 



Report of the botanists, G. E. Stone and N. F. Monahan i Massachusetts Sta. 

 L'/il. 1903, pp. 0-12). — Brief summaries are given of the principal investigations car- 

 ried on by the authors during the period covered by the report. The season is said 

 to have been a peculiar one, and the absence of many common fungi is noted, while 

 others of Tittle serious importance were very prevalent. Brief notes are given on the 

 occurrence of raspberry cane blight; an unusual leaf spot of corn caused by the fun- 

 gus Helminthosporium inconspicuum; stem rots of carnations, asters, etc.; leaf spot of 

 English ivy due to Vermicularia tricJiella, and a leaf blight of horse-chestnut due to 

 PhyUosticta sj'h.-i ropsoidt <>. Notes are also given on the winterkilling of a number of 

 hitherto considered hardy plants and a brief statement made regarding the experi- 

 ments conducted at the station on the effect of electricity on plant growth. 



FERMENTATION— BACTERIOLOGY. 



Report of the Agricultural Bacteriological Laboratory of the Ministry of 

 Agriculture for 1901, A. Tueoktistov {Setek. Khoz. I Lyesov.,211 (1903), Nos. 10, 

 />/>. 184-208; 11, pp. 285-316). — Investigations pursued during the period covered by 

 the report embrace the following: Bacteriological investigations of herring brine, 

 virulence of bacteria which kill mice, fermentation of tobacco, lactic-acid investiga- 



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