243>« Journal of Applied Microscopy 



trates. A third bio-chemical character used was based upon the inoculation of 

 anti-streptococcic serum into rabbits to determine whether the animals were thus 

 protected against the different streptococci. The results of the experiments is 

 somewhat surprising, for he finds that with one exception the streptococci all 

 have the same characters, and are indistinguishable from one another. The one 

 exception is a streptococcus found in scarlet fever which proves to have ver)- 

 little power of ha;lomysis upon rabbit serum. The conclusion that all pathogenic 

 streptococci are identical or belong to closely identical types is a striking one. 

 It certainly could hardly have been anticipated beforehand, and shows the inad- 

 equacy of our present method of diagnosis. In a measure confirmatory of these 

 results is a paper by Aronson in the Berlin Klin. Woch. Oct. 27, 1902, experi- 

 menting with streptococci from scarlet fever, diphtheria, erysipelas, and acute 

 rheumatic fever. While his cultures at first showed different characteristics, 

 they were lost after cultivation. Aronson also concludes as to close relationship 

 of all species, since serum from a horse will minimize against all streptococci. 



H. W. C. 



Mouton. Rescherches sur la digestion chez That larger animals and plants serve as 

 ]es amibes et sur leur diastase intracellulaire. foQ^j {qj. j-^^j^ parasitic bacteria is well 

 Ann. de rinst. Past. 16: 457, 1902. ... 



understood, and it is interesting to read 



of a series of observations showing an instance in which the bacteria themselves 

 serve as the food. The author has studied amoeba which he has found in garden 

 earth. Experience has shown that it is impossible to keep amoeba alive in pure 

 cultures. But the author finds that they can be kept alive if a quantity of certain 

 bacteria, B. coli being the one used here, is mixed with the amoeba, the amoeba 

 feeding upon the B. coli and thus sustaining themselves in culture. It is the 

 digestion of the bacteria that the author studies, and the purpose of the 

 present experiments was to determine whether the amoeba produces a proteolytic 

 enzyme by which they digested the bacteria. The author's method of experi- 

 menting is as follows : A mixed culture of amoeba and bacteria is placed in a 

 centrifuge and rapidly rotated. The liquid is then removed and the sediment is 

 mixed with two or three times its volume of glycerine and again centrifuged. 

 The glycerine dissolves from the amteba the enzymes present, and the solution 

 may be subsequently used for experimental purposes. Tests of the glycerine 

 extract, in the presence of chloroform to prevent the growth of micro-organisms, 

 show the presence of an enzyme which rapidly digests fibrin and other proteids, 

 the results being quite similar to that of trypsin digestion. The conclusion would 

 of course have been anticipated, but the method of obtaining a proteolytic enzyme 

 from micro-organisms is new. h. w. c. 



„, ^ ,^- V, , • J The author has made an examination 



Weber. Die bakterien der sogenannten ster- 



ilisirten Milch, u. ihre Beziehunzen zu den of 150 samples of Sterilized milk from 



Magendarmkrankheiten der Sauglinge. Arb. gj j^^ dift'erent dairies in Berlin. In no 

 a. d. Kais. Ges. A. 17, lob, 1901. " 



dairy does he find that all samples of 



milk are sterile. Eighteen species of bacteria are isolated from 150 samples. 



These bacteria all have the power of peptonizing casein, producing putrefactive 



and other injurious changes in the milk. He concludes, therefore, that the in- 



