264 EXPEKIMENT STATION EEOOBD. 



The cbief work reaction which causes contraction depends upon the forma- 

 tion of lactic acid. As yet the origin of the lactic acid is not known. Probably 

 it does not come direcl.y from glycogen or from dextrose. When muscle is 

 stimulated and fatigued, the lactic acid disappears, oxygen being taken up and 

 carbon dioxid given cu, not, however, by means of simple combustion but 

 through the regeneration of the lactic-acid-yielding substances coupled with an 

 oxidative process. Muscular contraction is apparently brought about by a 

 swelling which is itself brought about by the presence of the acid. The laws 

 of the increased volume phenomena are the same as those for the dilution of 

 concentrated solutions. In this case, as in the case of the muscle, practically 

 all the energy changes can be noted as work. 



A discussion follows the paper. 



The influence of the temperature of the surrounding air upon carbon 

 dioxid excretion in man — a contribution to the subject of heat regnlation, 

 L. Sjosteom {Skand. Arch. Physiol., SO (1913), No. 1-3, pp. 1-72, figs. 13).— 

 Extended investigations are reported which led to the following conclusions: 



Variations in the carbon dioxid excretion of a fasting man at rest, though 

 not absolut^y vrithout muscular movement, are not influenced by surrounding 

 temperature, so long as shivering is absent. Shivering causes an increase in 

 the oxidation processes of the body for the purpose of maintaining constant 

 Liody temperature, the increase being proportional to the intensity of such 

 movement The increased heat production caused by such means is not suflS- 

 cient to maintain constant temperature in the body when heat is withdravni 

 in large quantities. Shivering is probably brought about, too, by nervous re- 

 action in which the temperature condition of the skin plays a part. Whether 

 or not higher temperatures than the surrounding air, 30 to 31° C, caused 

 changes in the intensity of metabolism could not be determined from the ex- 

 perimental data reported. The author is of the opinion that possibly indi- 

 vidual peculiarities had an effect upon this. 



The influence of body position upon respiration in man, G. Liljestband 

 and G. Woixin (Skand. Arch. Physiol., 30 (1913), No. 1-3, pp. 199-228, figs. 

 S). — According to the conclusions drawn by the authors from their investiga- 

 tions, respiration is influenced in a typical way by the body position, even in 

 a condition of muscular rest and fasting. 



Both the frequency and the volume per minute are greatest when standing, 

 less when sitting, and still less when lying down. The number of respirations 

 per minute was lower when lying upon the stomach than when lying upon the 

 back. The changes in ventilation are in large measure directly dependent upon 

 the change in frequency of respiration. The changes in frequency and in ven- 

 tilation when frequency was constant for different body positions were not 

 caused by variations in carbon dioxid production. 



ANIMAL PRODUCTION. 



Problems of genetics, W. Bateson (New Haven, Conn., and London, 1915, pp. 

 IX-{-258, pis. 3, figs. 11). — The chapters included in this volume are as follows: 

 The problem of species and variety; meristic phenomena; segmentation; the 

 classification of variation and the nature of substantive variation ; the mutation 

 theory; variation and locality; local differentiation; climatic varieties; the 

 effects of changed conditions ; the causes of genetic variation ; and the sterility 

 of hybrids. 



Experimental studies of the inheritance of color in mice, C. C. Little (Car- 

 negie Inst. Washington PuJ). 119, 191S, pp. 11-102, pis. 5). — The conclusions of 



