ZOOLOGY A.ND BOTANY, MICROSCOPY, ETC. 403 



tion also occurs, but more slowly. In dilutions of I : 50, normal sera 

 will still cause agglutination to take place, but more slowly. No agglu- 

 tination takes place if normal sera be diluted 1 : 100. Heating for 

 half an hour to a temperature of 56° will destroy all the agglutinating 

 power of a normal serum. Sera of goats, sheep, rabbits, and other 

 animals, possess the same property. In order to avoid diagnostic errors 

 the following conditions should be observed : dilutions of 1 : 30 should 

 uot be used ; dilutions of 1 : 50 should be observed only within the 

 first 5 hours ; all errors may be avoided by heating the serum to 56° for 

 half an hour. 



Survival of Intestinal Organisms in Cooked Meats* — E. Maurel 

 has carried out some researches, with a view to finding the length of time 

 for which certain bacilli retain their powers of reproduction upon the I ood- 

 stuffs obtainable at a French cooked-meat shop. Only those meats which 

 were destined for eating without further cooking were used. Samples in 

 good condition were taken, and cultivations made in order to ascertain 

 what micro-organisms were already present. The meat was then steri- 

 lized in an autoclave. The effectiveness of the sterilization was tested 

 by cultivations. Then the surface of the meat was inoculated, in one 

 series with Bacillus coli, in another with B. typhosus. It was found 

 that the former retained its reproductive powers for twenty-four hours, 

 probably for several days. The latter was less resistant, but appeared to 

 retain power of reproduction for at least twenty -four hours. 



Resistance of Micrococcus melitensis to Lactic Ferments.f — P. 

 i >arbois has made observations upon the length of time in which Micro- 

 coccus melitensis will survive in milk inoculated with a lactic ferment. 

 He finds that this organism may be recovered up till the eighteenth day 

 after inoculation. This is both of considerable theoretical interest, as 

 this organism is in many conditions fragile ; and of practical importance 

 as showing that butter, cheese, cream, etc., prepared from a contaminated 

 milk may continue to be infective for two or three weeks. 



Thermobiosis.J — A. Ambroz gives a comprehensive review of the 

 literature of the subject. The first historical record of the phenomenon 

 was published in 1774 by Sonnerat, who stated that certain fish were 

 capable of living in water at f>9° C. In recent times there have accumu- 

 lated numerous records of micro-organisms, which are capable of increas- 

 ing and multiplying at a temperature higher than that at which albumin 

 coagulates. In 1837, algaa living in the hot springs at Carlsbad were 

 described. Other instances of the occurrence of various micro-organisms 

 in springs at high temperatures are recorded. Recently bacteria have 

 been isolated from wells at Vranje in Servia, of which the optimum 

 temperature was found to be 72° C. From soil, faeces, spring water, milk, 

 and other sources, organisms have been obtained, which grow best at 

 temperatures of 60 to 70° C. Some investigations have been carried out 

 and some hypotheses propounded, with a view to elucidating the abnorm- 

 alities of metabolism in these organisms. Full references are given. 



-■ 



+ 



.. Soc. Biol. Paris, lxix. (i'JIU) pp. 574-7. t Op.cit., !xx. (1911) pp. 102-4 

 alt. I. Bakt., xlviii. (1910) pp. 258-70. 



