ANIMAL PUODUCTION. 1071 



mmiber of bacteria (at u time tlioy luay bo called 'fresh') than tlie eg},'.s of 

 tlie other iiiontlis of the year, |>arti(ul;iily when conipan'd witli the ej,'f;s laid 

 diirliij; the niontlis of April. .May, and June. This corroborates the oi)ini()n of 

 cfifj packers, who invariably prefer April, May. and June eR.i,'s to those produced 

 dnriny the other mouths of the year. . . . 



•'The fact.that an esg contains bacteria does not mean that it is worthless. 

 The question is mainly whether or not they are present in large numbers, and 

 if present iu small numbers, whether or not they are likely to multiply. 



" Bacteria which are commonly found iu eggs do not multiply at low tempera- 

 tures. An egg that is kept at 34° F. is safe from dectmiiiosition. Repeated 

 experiments have shown that the rapid growth of bacteria does not occur until 

 the temi)erature is raised over n.j". While there is some growth at tempera- 

 tures lower than 5;j°, it is very slow. At the temperature of 98.G° the bacteria 

 in the egg nuiltiply rapidly. In order to demonstrate the rapid multiplication 

 of liacteria resulting in decomposition, a dozen (January) eggs were taken, and 

 in six of them snuill holes were made and into each egg bacteria from a rotten 

 egg were introduced on a platinum loop. These holes were sealed with wax and 

 the eggs thus infected, together with the six untreated eggs, were placed in an 

 ineubator running at a temperature of 110°. In 48 hours tlie G eggs which had 

 lie(>ii infected were so badly decomposed as to be very offensive and the re- 

 maining six showed no changes in them." 



Directions are given for using water glass in the preservation (jf eggs. 



Humane slaug'htering-. Improved foreign methods (Mo. Cons, and Trade 

 A*/''"--. I''. N-l, l!ii>^, .\o. J.i.s, pp. 10.'}-/ IS). —This is a report by American con- 

 sular ofticei's on the methods of slaughtering animals for food in France, 

 (lermany, Italj-, Belgium, United Kingdom, Austria, Russia, the Netherlands, 

 British India, China, and Japan. The operations vary widely iu cities of the 

 same country, there being api)arently no uniform laws, though the cities have 

 regulations and restrictions. 



Recent theories and experiments on heredity and inheritance, II. Diunk- 

 WATKij (llrit. Med. Jour., lUOH, \o. Zy.HK pp. l.l.iS-t.^'il ). — A review of the 

 principal theories that have been propounded. 



The possibility of inheritance through the placental circulation instead 

 of through the germ cells, F. T. Lewis (Amcr. Xat., .'i2 (HKJS), \o. J,!)',, pp. 

 J.l'i~l.!(i). — Attention is called to the recent work of Theoludd Smith and 

 others in the inheritance by mice, guinea pigs, and rabbits of innnunity to 

 toxic substances. As this immunity is inherited through the females only it is 

 suggested that immunity and also hemo]ihilia may be caused by a substance in 

 the blood and thus be inherited through the somatic elements. As the next 

 generation only are immune, it is not a case of inheritance t»f aoiuired char- 

 acters as ordinarily understood by biologists. 



Recent researches on the determination and heredity of sex, E. B. Wilson 

 (.S'f •(>•/( rr'. /(. scr., 29 { lUOU) . Xo. 732, pp. 53-10, fig.s. 2).— This is the address of 

 the vice-president of the American Association for tlu; Advancement of Science, 

 at Baltimore. DtK-ember, lOOS. 



Sex production is a phenomenon of heredity. Every form of heredity is in 

 a sense a response of the developing organism to external stimuli. Male ami 

 femah' arc? relative terms and denote teiulencies only. The work of earlier in- 

 vestigators on this subject was not of sex delermination but rather of suppres- 

 sion of one set of organs. .More recent investigation on insects, amphibia, 

 manunals. I'.ryophyta. and pollen grains of higher plants has led to negative re- 



s.-,(;7()— No. 1 1 —OU 



