G98 EXPERIMENT STATION RECORD. 



animalfl which assist in tlie destruction of the larva?. According to the author' 

 ol)servations the greatest distance to which adult Anopheles fly in India is a])out 

 three-fourths of a mile. 



Variations induced in larval, pupal, and imaginal stages of Bombyx mori 

 by controlled varying food supply, V. L. Kellcxk; and li. G. Bell {Srinice, n. 

 ner., IS (1903), Xo. 467, pp. 741-74S). — The experiments reported in this paper were 

 undertaken for the purpose of determining the relation between the; quantity and 

 quality of food and the development and variations in silkworms. The changes in 

 the (juality of food were brought about ])y feeding lettuce in the place of mulberry 

 leaves, whiU' in anotiier series of experiments the (juantity of the mun)erry leaves 

 fed was made Xo vary according to desired changes. 



These exi)erimentvS were carried on for a period of 3 years. The characters studied 

 in the silkworms. for the purpose of judging of the effect of these varied conditions 

 were the size and weight of the larvae, the promptness of molting and spinning, fer- 

 tility and mortality. Silkworms fed on lettuce leaves appeared to adapt themselves 

 quite readily to this diet; the larval skin, however, was thinner usually, and the 

 time consumed in metamorphosis was twice as long as that of larvfe feil on mull)erry 

 leaves. In the silkworms fed on mulberry leaves a definite and constant relation 

 ■was observed between the amount of feed and the size. With regard to the fertility 

 of the eggs it was found that the better nourished the insects the more fertile the 

 eggs. 



Experiments in sericulture in Tunis, F. Verry {Bui. Dir. Agr. et Coin. [Tunisl, 

 8 {lHOo), X(j. ,?.9, pp. 501-509). — The eggs of a number of varieties of silkworms, 

 including the Bagdad and the Yellow Chinese races, were obtained for the purpose 

 of testing their adaptability to the conditions in Tunis. Good results were obtained 

 in the quantity and quality of silk produced. 



FOODS— NUTRITION. 



Experiments on the metabolism of matter and energy in the human body, 

 W. O. Atwater and F. G. Benedict {U. S. Dept. Agr., Office of Experiment Stations 

 Bui. 136, pp. 357, pi. l,figs. i^).— Continuing previous work (E. S. R., 13, p. 972), 

 the details are reported of 21 experiments, made with the respiration calorimeter, 

 upon the metabolism of matter and energy in the human body. In some of the 

 experiments reported carbohydrates predominated in the diet, and in others fat, 

 while in a smaller number of cases the subjects fasted. In a number of tests the sub- 

 jects rested, and in others work was performed. 



Modifications in the apparatus and experimental methods adopted since the pre- 

 vious report are described, and the results of the present experiments and those pre- 

 viously reported are discussed at length, the subjects including among others the 

 demand of the body for nourishment, the elimination of carbon dioxid, water, and 

 heat; body temperature; heat production r. heat elimination; respiratory and carbon 

 dioxid thermal quotients; amounts of energy derived from different nutrients; fats v. 

 carl)ohydrates as protectors of body material and as sources of energy for muscular 

 work; carbohydrates and fats v. protein as sources of energy for muscular work; and 

 the efficiency of the body as a machine. The conservation of energy in the body is 

 also spoken of and the experiments with the respiration calorimeter are regarded as 

 a demonstration of the application of this law to the living organism. 



The accuracy of the apparatus is shown by the fact that in the check experiments 

 in 1902, when alcohol was burned in the respiration chamber for a period aggregat- 

 ing 380 hours and 44 minutes, the total estimated heat was 34,230 calories and the 

 amount found 34,288 calories, or 100.2 per cent of the theoretical value. The theo- 

 retical amount of carbon dioxid produced was 10,984 gm. and the total amount 

 measured was 10,982.3 gm., or 100 per cent. The theoretical amount of water due to 

 combustion of alcohol was 7,974.8 gm., and the amount measured 8,225.9 gm., or 



