1024 KXPKRIMENT STATION KECORD, 



AGRICULTURAL BOTANY. 



A statistical criterion for species and genera among the bacteria, C E. A. 

 WiiNsi.ow ^|{|(1. Tdniij Hot. Cltth, .id {I'JO'.h, Xo. /, ;'/'• •H--V.n. — Attention is 

 called to the almost infinite numijer of variations in different groups of bac- 

 teria and tlie difficulty of tlieir classification. Tlie autlior lias attempted tlieir 

 classification by the statistical method and has de"Oted several years to work 

 on the classification of the family Coccacea; (see p. 1079). He has found that 

 others are pursuing the same method for limiting the species of other groups of 

 bacteriii, and he concludes that in groups like bacteria and perhaps in some 

 classes of fungi, which have differentiated along physiological rather than 

 morphological lines, differences in metabolism may have the same systematic 

 importance that is given to gross structural differences in other groups. 



The characters vary in each particular group and their value for classification 

 must be determined by a survey of their relationships. The most satisfactory 

 method of studying the systematic relations of these simple and variable forms 

 is by obtaining quantitative measurements of a number of characteristic prop- 

 erties in a large series of individuals and by statistical analysis of the results. 



The author believes that generic names may be given to the larger groups of 

 organisms which have several apparently iudeiiendent properties in common, 

 and specific names may be reserved for the smaller groups, characterized by 

 variations in single uncorrelated properties. 



Studies on bacterial enzyms, H. Zikes (WclniscJir. Brau., 25 (1908), \o. 2.'i, 

 PI). S6 1-366). — A summary is given of information regarding the occurrence and 

 function of bacterial enzyms. 



The proteases of plants, VI, S. H Vines {Ann. Bat. [London], 23 (i;)09). 

 No. 89, pp. 1-18). — This is the sixtli contribution of the author's on this .subject, 

 those previous having been noted ( E. S. R., 19, p. 931). From his studies the 

 author is led to reject the hypothesis of the occurrence of trypsin in plants, 

 and he proposes in its stead the theory that the proteases of plants belong to 

 two groups, the peptases and the ereptases, and claims that this view is sup- 

 ported by considerable direct and indirect evidence. 



The ereptases are enzyms which are readily soluble in water and in alcohol 

 up to about 65 per cent. Their digestive activity seems to be exclusively pep- 

 tolytic and to be especially associated with acid media. Thus far the author 

 has been unable to give an approximate reaction range for plant ereptase. 



The peptases are proteases the digestive activity of which is limited to the 

 peptonization of the more complex proteins. There appears to be some ground 

 for believing that there are two kinds of peptases, which differ from each other 

 in the mode of their occurrence and in the relation between their respective 

 digestive activities and the reaction of the medium. The first kind exists in 

 the tissues of plants, fruits, seeds, latex, etc., and to this is given the name 

 endopeptase. The other kind is found in the excretions of plants, as in the 

 pitcher liquid of Nepenthes, and is designated as ectopeptase. 



The author concludes the series of papers by calling attention to the analo- 

 gies between proteolytic enzyms of plants and those of animals. The enzym 

 which he has called ectopeptase agrees in all essentiaT properties witli animal 

 pepsin. It is not so easy to find an animal analogue for endopeptase, but it 

 ar»pears to correspond fairly well with the peptonizing factor in trypsin. 



Concerning fungus desamidase, II. Pringsheim {Biocltcm. Ztschr., 12 {1908), 

 No. 1-2, lip. 15-25). — According to the investigations of the author and others, 

 various fungi, especially yeasts and Aspergillus niger, have the ability of split- 

 ting off ammonia from nitrogen-containing substances, particularly from amino 

 acids. The action is essentially enzymic, and the name desamidase has been 



