672 EXPERIMENT STATION RECORD. 



The enei-gy problem from the standpoint of muscular work and intellec- 

 tual work, II. Renauld (2. Cong. Intcrnat. Uyg. Aliment., Bruxelles [Proc], 1 

 (1910), Sect. 1, pp. 11-lIt). — ^According to the author's summary, the same 

 general laws which govern muscular work hold also for mental work. 



The brain, he concludes, is subject to osmosis, as are the other organs of the 

 body. As the muscle cells when they become active utilize some form of 

 carbohydrate, so the cerebral cells utilize a special substance, chromatin. 

 Morphological changes corresponding to those in the glandular cells which pro- 

 duce external secretions also take place in the coi'tical cells according as the 

 latter are in a state of psychic activity or repose. Psychic activity, like mus- 

 cular activity, occasions an increased flow of blood through the organ and an 

 increase in waste products, as is shown by the highly toxic character of the 

 urine in subjects performing severe intellectual work. But whereas in the case 

 of muscular activity the chemical reactions and heat liberation can be local- 

 ized and measured in the muscle itself, this has not yet been done in the case 

 of intellectual activity. In the latter not one set of cells, but probably the 

 entire neuro-muscular system, is called into play. In short, while it has been 

 demonstrated that the law of the conservation of energy holds in mental work, 

 it has up to the present time been impossible to measure the exchanges which 

 accompany it. 



Calorimetry with human subjects, G. Weiss (2. Cong. Internat. Hyg. Ali- 

 ment., Bruxelles [Proc], 1 {1910), Sect. 1, pp. 3.'i-4'f). — ^A historical and critical 

 survey. 



Friction in the bomb calorimeter, H. A. Eoeslee (Amer. Chem. Jour., Jf4 

 {1910), No. 1, pp. SO-^4; ahs. in Chem. News, 103 {1911), No. 2667, pp. 2, 3).— 

 A method for determining the heating effect due to the friction of the stirrer 

 in bomb calorimetry work was evolved, and the results of a number of deter- 

 minations reported. The magnitude of the rate of rise in temperature, due to 

 such friction, does not affect the accuracy of the heat determinations, according 

 to the author, provided it is uniform throughout the time of the determination. 



ANIMAL PEODTJCTION. 



Breeding farm animals, F. R. Marshall {Chicago, 1911, pp. 287, figs. 49). — 

 As stated in the preface, " the main object of this book is to direct attention 

 away from profitless speculations that have necessarily characterized some 

 earlier books, and to stimulate interest in the more tangible, the physical basis 

 of heredity. ... It has been the aim to limit discussion to points upon which 

 scientific opinion is quite well agreed, though this has not been altogether 

 possible." 



In the chapters on " germ cells," " the offspring during gestation," and 

 " Mendel's law " will be found such information as the author has gleaned 

 from the biological field that is of value to the practical breeder. The author 

 shows that a scientific study of the physical aspects of heredity lead to con- 

 clusions that are in accord with the teachings of the men who have produced 

 the best types of horses, cattle, sheep, and swine. Among the chapters devoted 

 to the practical side of breeding are the following: Pedigrees of breeding ani- 

 mals, foundation and management of a breeding business, and breeding associa- 

 tions. 



On the interrelations of genetic factors, W. Bateson and R. C. Punnett 

 {Proc. Roy. Soc. [London], Ser. B, 84 {1911), No. B 568, pp. 5-8).— Results 

 obtained with plants examined in the light of the presence and absence hypothe- 

 sis showed two distinct conditions, first, a system of partial coupling under 

 which two factors are generally associated, and a system of complete repul- 



