ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 97 



formation. The actively living cell consists of cell-wall, cell-plasma, 

 and granules. The cell-wall is a progressive formation, and becomes 

 finally a rigid structure. The cell-plasma is hyaline or very finely 

 granular. The granules are refractive, spherical, and stain vividly with 

 rosein ; they may participate in cell-division, and may be extruded from 

 the cell through the cell-wall. Their indiscriminate distribution, and 

 their existence in the surrounding medium, negative the view of their 

 nuclear nature. In a limited sense they may be regarded as excretory 

 products ; but inasmuch as they so often take part in the division of the 

 cell, and as the embryo, on emergence from the spore-case, contains 

 a granule, it is highly probable that these granules are fundamental 

 elements of the bacterial cell. 



Resorption of Cells.* — Under this title M. E. Metchnikoff describes 

 another phase of phagocytosis. Beginning with the appearances ob- 

 served on injecting spermatozoa into the peritoneal sac of guinea-pigs, 

 he passes on to describe the resorption of the chromocytes of geese in 

 the peritoneal sac of guinea-pigs ; the antagonism of the antisomes of 

 the guinea-pig and the chromocytes ; the resorption of the chromocytes 

 in the organism of guinea-pigs possessing antisomes in their juices ; and 

 lastly, antileucocytic serum. The observations and experiments are 

 summed up as follows: — Cell-resorption is chiefly the work of macro- 

 phages, which can deal with living as well as dead cells. The mono- 

 nuclear phagocytes seize hold of cells by means of small pseudopods. 

 When injected into the peritoneal sac, the chromocytes are almost ex- 

 clusively devoured by macrophages, which find their way by the usual 

 channels into the blood, wherein the agglutinating and hemolytic sub- 

 stances are principally formed. The immunising substance (substance 

 sensibilisatrice) is probably an excretion from macrophages which have 

 finished digesting. The extracellular dissolution of geese-chromocytes 

 can be prevented in guinea-pigs whose body-juices are hemolytic. This 

 fact indicates that the excreted immunising substance circulating in the 

 blood requires the intervention of another substance which is more 

 closely connected with phagocytes. The resorption of macrophages calls 

 forth the formation of serum, which destroys polynuclear leucocytes and 

 Ehrlich's cells (Mastzellen). 



Bacterial Disease of the Sugar-Beet.f — Clara A. Cunningham has 

 studied a disease of the sugar-beet which prevailed in the United States, 

 and finds it to be caused by an organism having the form of a small 

 bacillus ■ 9-1 ■ 3 fx long by ■ 5-0 ■ 8 /* broad, single or in pairs, and 

 motile, but showing neither spores nor fiagella by any process of staining. 

 The author is doubtful whether it is identical with the organism named 

 Bacillus Betse, or with that which produces bacteriosis gummosa, de- 

 scribed by Sorauer, Kramer, and Erwin F. Smith. Another organism 

 resembling a Leuconostoc was found in the diseased beets. 



Bacterial Disease of the Haricot.! — The haricot crops in the neigh- 

 bourhood of Paris are greatly infected by a disease known as la graisse, 

 which M. Delacroix finds to be due to a Schizomycete apparently identical 



* Ann. Inst. Pasteur, xiii. (1899) pp. 737-69 (2 pis.). 



t Bot. Gazette, xxviii. (1899) pp. 177-92 (5 pis.). Cf. this Journal, 1S98, p. 462. 



X Comptes Kendus, cxxix. (1899) pp. 656-9. Cf. this Journal, 1898, p. 115. 



Feb. 21st, 1900 H 



