ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 233 



The author found that reproduction beginning atlO°C, increases 

 rapidly to 37° C, where it reaches its maximum rate with a generation 

 time of seventeen minutes ; this rate is nearly constant up to 45° C, 

 when it falls rapidly and reproduction ceases at 49° C. The values of g 

 in the lower temperatures vary greatly, owing partly to the degeneration 

 of the cells at these temperatures, and also to the difficulty of keeping 

 constant low temperatures for the long time necessary to obtain a 

 considerable number of generations. Degeneration and tendency to 

 grow into threads, and the failure of some cells to grow, render the 

 value of g above 45° C. unreliable. 



Under constant conditions the rate of growth is constant as far as 

 thirty-eight generations, and all offspring continue to divide at the same 

 geometrical ratio as the parent bacilli. The author considers that it is 

 not probable that any body temperature during fever can be high 

 enough to alter the rate of reproduction of pathogenic bacteria. 



AVith B. coli there is no correlation between motility and rapidity 

 of division. 



Myxococcus Javanensis.* — E. de Kruyff observed in course of a 

 research on the cellulose-fermenting bacteria — using the method of Van 

 Iterson — that after about three weeks there appeared on the paper plates 

 a number of small round granules of a pale red colour. Microscopically 

 these were seen to contain spores, two to three of which were usually 

 joined together in chains ; wdien brought in contact with a drop of w T ater 

 the spore-cases were dissolved and the spores escaped. 



If these were transferred to agar containing NH 4 P0 4 and KHP0 4 , 

 red colonies appeared after three days : temperature between 25° and 

 29° C. gave the quickest growth, but growth also occurred at 40° C. ; 

 the temperature had no effect on the production of red colour. 



The colonies, which were composed of a mass of bacteria, had a 

 slimy consistence, and moved over the surface of the agar plate like the 

 Plasmodia of mycetozoa. The bacteria were non-motile and usually 

 curved, 6-7/x long by ' G/x. They grew well on various neutral media ; 

 they stained with ordinary aniline dyes. They form round or elongated 

 spore-cases, 70-100> in diameter, of a pale red colour. The spores 

 are round, 1 ■ 6/u. diameter, and usually arranged in chains. In hanging- 

 drop they were seen to grow in rods. 



Pathogenic Sarcina.t — B. Galli Valerio has isolated a sarcina from 

 the mucous secretion of the nose and pharynx of a man suffering from 

 chronic pemphigus (pemphigus a repetition) of the mucous membrane of 

 the nose and mouth. Films stained with carbol-fuchsin showed large 

 numbers of sarcina bundles among the cells of the epithelium and pus. 

 The organism stained by Gram's method ; individual cocci hadj dia- 

 meters of 1 • 5-2 /u, ; they were always extracellular. 



Agar plate cultures showed only colonies of this sarcina, though in 

 those prepared from the pharynx there were a few colonies of Micro- 

 coccus pyogenes. Colonies on gelatin at 20° were similar to those on 

 agar ; the medium was not liquefied. Broth is uniformly clouded at 



* Centralbl. Bakt., 2te Abt., xxi. (1908) p. 385. 

 t Op. cit., lte Abt., xlvii. (1908) p. 177. 



April 21st, 1909 it 



