580 EXPF.KTMF.XT s;TATTOX RErOTJD. 



iiiulcr the colors which least stiiimlalo the cliloroiiliyll I'liiictions of tho plants. 

 With the exception of peas, tlie total nitroj,'en and allmniinoid nitrojicn were 

 .greatest nnder the jzreeu and l)lue colored screens. 



The influence of shade upon the composition of plants, 11. ^\'. Tiiatciiek 

 {Jour. Indus, and Engin. Chem., 1 {1909), No. 12, pp. 801, 802). — In a previous 

 publication the author has referred to the effect of shade on the constituents of 

 the wheat kernel (E. S. R., 19, p. 43r>). In the ])resent paper an account is 

 given of investifjations carried on by the author and some of the assistants at 

 the Washinf^ton Experiment Station to determine the effect of shading on the 

 composition of i>otatoes, field peas, ennner, wheat, oats, and barley. 



Different densities of shade, lengths of time of shading, and crops have been 

 employed, and it has been found that except with i»lants which become very 

 dry in maturing, the moisture content is greatly increased under the shade. 

 There is also a higher percentage of ash in the shaded samples, except in the 

 case of oats, and a somewhat larger amount of crude i)roteln in the plants 

 grown under the sliade. 



The general effect of shading, whatever the texture of the material used 

 or the length of the shading period, is to increase the percentage of moisture, 

 mineral matter, and nitrogenous matter, with a deci'eased percentage of starch 

 or carbohydrates. However, the increase in other constituents is not directly 

 proportional to the decrease in starch. It is believed that the changes produced 

 l)y the shade are not simply a deterrence of the elaboration of starch or other 

 carbohydrates in the absence of direct sunlight, but that other physiological 

 changes are induced by the shading. 



Protein metabolism in plants and its relation to some physiological proc- 

 esses, F. Ehrlich {Landw. Jahrh., 38 {1909). Erf/tinzuiiffsh. 5, pp. 289-327). — 

 As a result of the author's studies on alcoholic fei'uientation, he arrives at the 

 conclusion that through the brealiing down of the sugars yeasts are supplied 

 with the energy required for building up proteids. Part of the sugars form 

 other carbohydrates, which, together with glycogen and amino acids, the yeast 

 forms into characteristic proteids. 



It is claimed that plants in general build their aromatic compounds chiefly 

 from the pi'oteids and that in a similar way, through the ])rotein metaliolism of 

 the plants, fusel oil and other nitrogen-free substances are formed. 



A comparative study on some vegetable diastases, C. (Jerber {Compt. Rend. 

 ^00. Biol. [Paris-]. 61 {1909), .Yo. ,^7, pp. .S'G7-86'.9 ) .— The results of a study of 

 the proteolytic enzyms of Pleurotus OHtreatus and of the paper mulberry are 

 given. It is shown that the rennet of the fungus is greatly favored by lime and 

 oxygen, is very sensible to allvalis, and slightly resistant to heat, while that of 

 the paper mulberry is less influenced by lime and oxygen, is l)ut slightly sensi- 

 tiA-e to alkali, and very resistant to high temperatures. 



Starch formation from sorbite by the Bosaceae, O. TREBorx {Bcr. Drut. 

 Bot. (IcscH.. 27 ( 1909), Xo. 8, pp. 507-.7//).— Attention is called to the fact that 

 sorbite can probably serve as a soui'ce of starch, as has been shown to be the 

 case for mannite and dulcite of other plants. Sorbite, however, is found only 

 in the fruit, while the others are found in all ])arts of the plants containing 

 them. 



As a result of a study of many species of rosaceous plants, the author con- 

 cludes that the ability to form starch from sorbite is a distinctive character- 

 istic of those species Jaelonging to, the tribes Pomers, Prunefp, and Spime'ejp. In 

 his investigations, no trace of starch which was made frfini s<irl)ite was to be 

 found in sjiecies of Rose;p and Rubeic. 



A critical examination of Sachs's method for using increase of dry weight 

 as a measure of carbon dioxid assimilation in leaves, D. Thoday ( Proc. Roy. 



