730 EXPERIMENT STATION RECORD. [Vol. 36 



for this form the term chlorostatolUhs is proposed. Statoliths may be special- 

 ized in shape, size, or behavior of the nucleus. 



The statolith apparatus consists of the whole system of statocytes occurring 

 in the various tissues of the plant, or else of cells themselves forming a tissue, 

 for which the term statenchyma has been proposed. Modifications and transi- 

 tional forms occur. The statolith is considered by the author as an intensive 

 mechanism, the simplest form of statocyte being the living cell itself, the 

 highest a cell containing relatively heavy bodies differentiated as to size and 

 mobility. Between these extremes occur may transitional stages. 



The influence of gaseous pressure on growth, Ethel McClennan {Proc. 

 Roy. Soc. Victoria, n. ser., 28 (1916), No. 2, pp. 2^5-250).— Seedlings of Pisum 

 arvense, observed while growing in a moist atmosphere at different air pres- 

 sures, showed retardation usually In one day, the amount of retardation 

 corresponding somewhat to the pressure. The plant accommodates itself to 

 the pressure and the growth rate gradually rises. The mechanical effect of 

 pressure upon turgor appears to be negligible as a factor determining growth. 

 The influence in this connection of an increase in the oxygen dissolved in the 

 tissues has not been determined. 



Concerning the transformation of pigments of plastids in (the) living tis- 

 sues of plants, V. N. Liubimenko (Lubimenko) (Izv. Imp. Akad. Nank {Bui. 

 Acad. Imp. Soi. Petrograd), 6. ser., 9 {1915), No. 10, pp. 933-935).— This is a 

 preliminary report of the results of investigations which will later be published 

 in detail. 



The author states that all the transformations of pigments of plastids in the 

 living tissues of i)lants are determined by the activities of oxidizing and re- 

 ducing enzyms of the cell protoplasm, and the accumulation of a given pigment 

 depends on the relation between the energy of oxidizing and reducing reactions 

 in the cell. Particularly, the quantity and accumulation of chlorophyll In 

 plastids in the presence of normal food supply is determined by the intensity 

 of oxidizing reactions in the cell. This also explains the connection between 

 greening and temperature. 



Light does not play a direct part in the chemical transformation of leuco- 

 phyll into clilorophyll, nor is there a direct correlation between the quantity 

 of chlorophyll and the energy of growth. The author emphasizes the presence 

 of a special enzym in the juices of the green plants provisionally termed by 

 him antioxidase. It paralyzes the oxidizing action of peroxidase on the 

 pigments of plastids and, unlike peroxidase, is highly sensitive to antiseptics. 

 Morphological differentiation of the organisms of the higher green plants, it 

 Is said, is accompanied by their physiological differentiation in the sense of 

 different intensity of oxidizing reactions. From the physiological viewpoint, 

 plastids show a considerable independence with regard to the cell protoplasm 

 and may be compared with leucocytes in animal bodies. 



Concerning the mechanism of photosynthesis, A. A. Kikhtee (Richter) 

 and E. M. KoLLEGORSKAfl {Izv. Imp. Akad. Nauk {Bui. Acad. Imp. Sci. Petro- 

 grad), 6. ser., 9 {1915), No. 5, pp. 457-467). — A new method for quantitative 

 studies of photosynthesis is described by the authors, in which a specially con- 

 structed apparatus and cultures of Photohacterium italicum were made use of. 

 They come to the conclusion that plants differing in their ecological relations 

 i-equire the same initial intensity of light for the decomposition of carbon dioxid. 

 It is noted, however, that with those plants which are enabled to concentrate 

 light by n)eans of special anatomical arrangements the intensity of light neces- 

 sary for the separation of oxygen in photosynthesis may be much lower than 

 with plants lacking such arrangements. 



