ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 63 



destroyed by desiccation. It grows well only on blood media such as 

 blood agar and blood broth. After a few days' growth involution forms 

 are abundant. Inoculated on animals it produces a fatal septicaemia, 

 but it is possible to vaccinate the animals against this result by the 

 injection of gradually increasing doses of the bacillus, and the serum of 

 the immunised animals possesses a markedly curative action, even 

 after the injection of a fatal dose. 



In most of its characters, morphological and physiological, it has a 

 striking resemblance to the influenza bacillus, but the serum of animals 

 immunised against the bacillus of Pfeiffer has neither a curative nor a 

 preventive action. 



Endotoxin of Bacillus Diphtheriae.*— L. Cruveilhier finds Loeffler's 

 diphtheria bacillus is possessed of an endotoxin which is quite distinct 

 from the soluble toxin. A very small dose kills guinea-pigs within 

 24 hours. The method of obtaining the endotoxin was to make an 

 emulsion of a 24-hours' old agar culture, and then heat the emulsion 

 in an autoclave at a temperature of 100°-105° C. for 15 to 20 minutes 

 in order to remove any trace of the soluble toxin. When cold the 

 solution was filtered. 



Flugge's Fluorescing Bacilli.t — The general characters of the two 

 fluorescing bacilli of Fliigge, B. fluorescens liquefaciens and jwtridus, 

 says E. Griffon, are as follows : — They do not form spores, are Gram- 

 negative, the cultures exhale a f secal odour, have an alkaline reaction, and 

 in many media there is a beautiful green fluorescence. One liquefies 

 gelatin, the other does not. Owing to this last property, to differences 

 in the amount of the green pigment, the rate of growth, the scum on 

 broth, the amountof the deposit, the pathogenicity to animals, especially 

 rabbits, some bacteriologists were led to make several varieties of these 

 bacteria and even to distinguish certain new species, such as B. cauli- 

 vorus, brassic&vorus, seruginosus, etc. The author deprecates this 

 multiplication of species, and holds that these fluorescing bacteria, so 

 pathogenic to certain plants, are only varieties of B. fluorescens and 

 putridus. The author seems inclined to make one species only, B. 

 fluorescens. He points out that it is a saprophyte, which adapts itself 

 very readily to parasitism, and the differences in its biological characters 

 are due to the reaction and composition of the soil or medium, to the 

 temperature and humidity of the atmosphere, and to the greater or lesser 

 resistance of the plant attacked. 



Determination of the Bovine or Human Origin of Tuberculosis.^ 

 A. Calmette and C. Guerin are of opinion that human and bovine 

 tubercle may be differentiated by the two following criteria. Bovine 

 tubercle may be cultivated with facility on ox-bile ; when injected into 

 the udder of goats, bovine tubercle causes a severe mammitis followed 

 by the death of the animal, while human tubercle produces only a mild 

 inflammation. 



* C.R. Soc. Biol. Paris, lxvi. (1909) pp. 1029-30. 



+ Comptes Rendus, cxlix. (1909) pp. 50-3. X Tom. cit., pp. 191-4. 



2 U 2 



