2G4 EXPERIMENT STATION EECOBD. [Vol.35 



On some new acarine parasites of rats, S. Hirst (Bid. Ent. Research, 6 

 {1U15), No. 2. pp. 183-190, figs. 8). — Four mites from i:ats are described for the 

 first time, one being a new species of Lselaps which occurs in Ceylon, India, 

 Africa, and South America, while the tliree others are larval forms of Trom- 

 bidiidiie collected in India. 



Two Mexican myTmecophilous mites, N. Banks (Psyche, 22 (1915), No. 2, 

 pp. 60, 61, figs. 2). 



FOODS— HUMAN NUTRITION. 



The infection of foods by bacteria, M. Boenand (Bui. Sac. Vand. Set. Nat., 

 5. ser., 50 (1915), No. 187, pp. 5S9-619). — Information is given regarding the 

 infection of milk, bread, eggs, meat, and drinks by pathogenic bacteria. The 

 most effective preventive measures are thought to be rigorous inspection of all 

 places where foods are prepared, handled, and sold ; protection from insects, 

 especially flies, by suitable screening; and personal inspection. 



Feeding experiments with Bacterium pullorum. — The toxicity of infected 

 egg's, L. P. Rettger, T. G. Hull, and W. S. Sttxbges (Jour. Expt. Med., 23 

 (1916), No. Jf, pp. 475-^8.9).— Earlier work by the senior author (E. S. R., 31, 

 p. 171) on the bacteriology of normal, fresh eggs is referred to and attention is 

 called to the widespread occurrence of Bacterium pullorum in eggs and its 

 possible significance in food poisoning. 



The investigation here reported consisted of two parts — a study of the toxicity 

 of B. pullorum when administered orally, either with food or by means of a 

 pipette, and also an investigation of the heat tolerance of B. pullorum in in- 

 fected eggs which were prepared for edible use by the ordinary processes of 

 boiling, coddling, frying, etc. 



Laboratory animals (rabbits, kittens, guinea pigs, and white rats) were fed 

 varying amounts of water suspensions of cultures of several different strains 

 of B. pullorum. Post-mortem examinations were made of the animals which 

 died and also of control animals, the results of the experiments being reported 

 in detail. 



The results of these tests showed that " eggs which harbor B. pullorum in the 

 yolk in large numbers may produce abnormal conditions, when fed, not only in 

 young chicks, but in adult fowls, young rabbits, guinea pigs, and kittens. The 

 toxicity for young rabbits is most pronounced, the infection usually resulting 

 in the death of the animals. In kittens the most prominent symptoms are those 

 of severe food-poisoning with members of the paratyphoid group of bacteria." 



Fresh eggs were infected with B. pullorum by injecting a small amount of 

 water suspension of the organism into the yolk by means of a sterile hypo- 

 dermic syi'inge. The infected eggs were incubated from three to five days and 

 then cooked in different ways, after which they were examined for the presence 

 of the organisms. These tests showed that poaching the eggs for from one-half 

 to four minutes rendered them sterile. Also no visible organisms were recovered 

 from infected eggs which had been scrambled. In the case of fried and coddled 

 eggs the organisms were recovered from the cooked eggs in some cases and not 

 in others. Even boiling the eggs for four minutes did not in every instance 

 destroy the organisms, this resistance being attributed by the authors to the 

 protection afforded by the shell, the egg white, and the yolk itself. 



The authors state that the possibility of danger from infection with B. 

 pullorum can not be ignored, especially in the case of invalids and young 

 children. 



" Ovarian infection of fowls is very common throughout this country. Hence 

 a large proportion of the marketed eggs are infected with B. pullorum. When 



