ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 477 



ing to the conclusion that acid organisms are not in the milk when 

 freshly drawn, but are a contamination from without. 



The author further examined bactcriologically the udders of two 

 cows, both derived from animals which had been condemned on the 

 result of the tuberculin test : neither cow was milked for some hours 

 previous to slaughter, a process which might have washed out micro- 

 organisms from the lacteal ducts. Inoculations were made into sterile 

 milk, on to serum, agar-agar, and gelatin tinted with litmus, from three 

 separate situations, — the upper glandular portion of the udder, the 

 milk cistern, and the beginning of the teat. In no case were either of 

 the three chief lactic bacteria found : an organism probably identical 

 with Conn's Micrococcus varians lactis, which does not appear to play 

 an important role in the souring of milk, was, however, isolated. 



Bacillus caseolylicus.* — Lochmann isolated a previously undescribed 

 bacillus belonging to the Coli group from the organs of a guinea-pig 

 which had succumbed to general tuberculosis after injection with a 

 cultivation of the B. tuberculosis. This organism, which he designates 

 B. caseolyticus, appears as small actively motile rods with rounded ends, 

 resembling the B. typhi abdominalis, and provided with 4-8 peri- 

 trichous flagella. It stains readily with the usual anilin dyes but does 

 not retain the colour when treated by Gram's method. In artificial 

 cultivations it is pleomorphic, sometimes grows out into long threads, 

 and is frequently vacuolated when old. It is a facultative anaerobe, 

 growing well at the room temperature, but better at 37° C, on all the 

 ordinary media. The bacillus is killed by exposure to 70° C. for five 

 minutes. Gelatin is not liquefied by its growth, which in stab culture 

 assumes the form of a nail with a flat head. Cultivations in broth 

 become uniformly turbid in a few hours, and after some days a deposit 

 is thrown down, whilst occasionally there is a suggestion of pellicle 

 formation. Indol is not formed. On potato a thick heaped-up layer 

 forms, which later becomes brownish in colour and spreads out laterally. 

 Milk is not coagulated by its growth, tut a large amount of alkali is 

 formed, and after about four weeks the milk appears to be peptonised, 

 although no peptones can be demonstrated by chemical tests. Gas pro- 

 duction is observed in media containing 2 p.c. of grape or cane-sugar 

 or lactose, and occasionally in media to which no sugar has been added. 



Forty-eight hour old broth cultivations of the bacillus are patho- 

 genic for mice and guinea-pigs in from 20 hours to 5 days when injected 

 subcutaneously, and in 4—5 days when introduced into the alimentary 

 canal [by feeding. Introduction of the bacillus into the healthy con- 

 junctival sac produces no pathogenic effect. In rabbits subcutaneous 

 inoculation merely provokes local suppuration not followed by general 

 infection. The author was unable to demonstrate the formation of any 

 soluble toxin. He differentiates the B. caseolyticus from the B. enteri- 

 tidis Gartner by the absence of toxin formation and the luxuriant 

 anaerobic growth. 



Efficiency of Pasteurisation.f — Eussell and Hastings studied the 

 destruction of bacteria in milk by means of heat, employing in their 



* Centralbl. Bakt., l^Abt., xxx i. (1902) pp. 385-8. 

 t Op._cit, 2" Abt., viii. (1902) pp. 462-9. 



