468 EXPEEIMENT STATION EECOED. 



and that the increase was only 5.61 calories per 100 calories in the case of grape 

 sugar. The experiments are discussed at length in relation to the work of 

 earlier investigators. 



The transformation of the glycogen into glucose by the animal tissues, 

 F. Maignon (Ann. Soc. Agr. 8ci. et Indus. Lyon, 1908, pp. 78-80). — From labora- 

 tory experiments the author concludes that muscles possess an amylase which 

 transforms glycogen into glucose. The transformation which takes place 

 constantly under normal conditions is accelerated by certain influences such as 

 crushing the tissue, which favors the intimate contact of the amylase and 

 glycogen. 



Fatigue poisons, W. Weichakdt (Uber Ermudungsstoffe. Stuttgart, 1910; 

 rev. in Zentbl. Gesam. Physiol, u. Path. Stoffwcchsels, n. ser., 5 (1910), A'O. 22, 

 p. 880). — The author has summarized the results of his numerous investiga- 

 tions which led him to conclude that fatigue is due to the production of a 

 specific toxin and that with this toxin an antitoxin may be prepared. 



ANIMAL PRODUCTION. 



The respiration calorimeter at the Institute of Animal Nuti'ition of the 

 Pennsylvania State College, H. P. Aemsby (Pennsylvania Sta. Bui. 10 Jf, pp. 

 3-16). — A previous description of the respiration calorimeter at the Pennsyl- 

 vania Institute of Animal Nutrition (E. S. R., 15, p. 10.37), which is used in co- 

 operation with this Department for the direct determination of the heat produc- 

 tion of cattle, is here substantially reprinted, with a discussion of check tests of 

 the accuracy of the apparatus which have been made. 



Two groups of alcohol check tests are reported, the first including those 

 made with the original form of the apparatus in which a considerable portion 

 of the moisture of the outgoing air was condensed in copper freezing cans, and 

 the second including tests of the present apparatus. 



"Apparently the most serious error in the heat determinations lies in the 

 measurement of the water vapor given off, and the more accurate determina- 

 tion of the latter by means of the aspirator samples reduces the average error 

 to a very small amount, although it does not seem to materially reduce the 

 range of the single results. The removal of the copper freezing cans appears 

 not to have afl'ected the average accuracy of the determinations. . . . The 

 excess of water vapor found in the samples taken by the meter pump seems 

 to be due to a drying out of the sampling pans and especially of their rubber 

 covers during the earlier hours of the experiment." 



" The results of a single experiment with the respiration calorimeter may be 

 regarded as accurate to within approximately the following percentages of the 

 total amounts determined: Carbon dioxid 0.5 per cent, water (in aspirator 

 samples) 6 per cent, heat 1 per cent." 



Influence of type and of age upon the utilization of feed by cattle, H. P. 

 Aemsby and J. A. Fries (Pennsylvania Sta. Bui. 105, pp. 3-22, figs. 6). — An 

 investigation with the respiration calorimeter at the Pennsylvania Institute 

 of Animal Nutrition of the relative efficiency of different types of animals as 

 converters of the energy of waste products into forms suitable for human food. 



To compare the beef type with the scrub as a meat producer a pure-bred 

 Aberdeen-Angus steer Si months of age, and a steer 11 months old, of the dairy 

 type, containing a large percentage of Jersey blood, were under observation 

 over 2i years. Both animals received similar rations, which consisted of hay, 

 bran, and mixed grains; the live weight was frequently taken, and the digesti- 

 bility of the total ration and the nitrogen balance were determined at intervals. 

 As regards the average percentage digestibility of the total dry matter, and 



