164 ^ EXPERIMEiSJT STATION RECORD. [Vol. 43 



was dead hi the pure honey in 24 hours, and after 10 hours all were dead in 

 the dilutions above 20 per cent. In the first series B. paratyphosus A exhibited 

 about the same degree of injury from the higher concentration as B. para- 

 typhosus B, being dead after 24 hours in pure honey and all dilutions above 30 

 per cent. In the second series, it was dead in the pure honey after 24 hours, 

 and in 10 hours in dilutions above 20 per cent. 



In the first series, B. dyscntcrice was destroyed in the pure honey in dilutiinis 

 above 40 per cent in 10 hours. In the second series, it was present in the pure 

 honey after 5 hours but absent after 10, and had disappeared in 5 hours in 

 all dilutions above 20 per cent. Other bacteria tested are B. fecalis alkaUgenes, 

 B. i)roteus vulgaris, B. suipestifcr, B. coU communis, B. entcritidis, and B. 

 lactis wrogenes. , 



" The failure of the organisms to die out as readily in the concentrated honey 

 as in the dilutions was rather surprising. A possible explanation of this sug- 

 gests itself in the physical state of the sugar particle in the honey. Assuming 

 the honey to have been a saturated solution, and this appears to have been the 

 case, there is a probability that we had here a colloidal solution with low 

 osmotic pressure. In such a solution, plasmolysis would take place relatively 

 slowly. When water was added, as in the dilutions, some of the colloidal 

 sugar passed over into molecular solution, the osmotic pressure increased, and 

 plasmolysis became more active." 



The results show the longevity of the typhoid-colon group in honey to be very 

 limited, and the probability of honey acting as a carrier of typhoid fever and 

 other diseases is very slight. 



Note on Eriopyga incincta Morr., F. M. Wadlky {Jour. Econ. Ent., IS 

 (1920), No. 1, p. l-lfS). — Biological notes are given on this cutworm-like cater- 

 pillar. It was abundant at Wichita, Ivans., during the spring of 1918, having 

 been found in great numbers in small areas of alfalfa and about the edges of 

 gardens. 



The present status of the control of Dermacentor venustus Banks in the 

 Bitter Root Valley, Mont., and new data concerning the habits of the tick, 

 R. R. Parker {Jour. Econ. Ent., IS {1920), No. 1, pp. 31-37).— This paper in- 

 cludes data on the migration of D. venustus and the reaction of engorged seed 

 ticks to light. 



FOODS— HUMAN NUTRITION. 



The food and drug manual {U. S. Dept. Agr., Bur. Chem., Food and Drus 

 Manual, Jan. 26, 1920, pp. 155, figs. Jf). — This manual, which supersedes one' 

 published in 1911, gives complete instructions regarding the procedure to be 

 followed by officials, analysts, and inspectors of the Bureau of Chemistry, U. S. 

 Depai'tment of Agriculture, in the enforcement of the Food and Drugs Act of 

 1906. 



The digestibility of chicken skin, E. F. Kohman and H. A. Shonle {Jour. 

 Biol. Chem., 41 {1920), No. 4, pp. 469-472). — Two metabolism experiments on 

 human subjects are reported in which from 65.1 to 67.5 per cent of the nitrogen 

 of the diet was supplied by chicken skin freed from extraneous fat and fried 

 in balls. The skin as used had 26.3 per cent of fat and 3.03 per cent of 

 nitrogen. The experimental period was preceded and followed by periods of 

 the same length in which the same amount of nitrogen was supplied by meat, 

 eggs, and milk, the basal diet throughout consisting of apples, prunes, oranges, 

 lettuce, tomatoes, sugar, tapioca, bread, potatoes, and butter. 



The percentage utilization of nitrogen in the three periods was 87.02, 85.61, 

 84.94, respectively, for one of the subjects and 83.69, 83, and 86.49 for the other. 



