November 12, 1915] 



SCIENCE 



681 



alcoholic with those of rats of normal parentage. 

 It is commonly claimed that in man, the children of 

 alcoholics are less teachable than children of nor- 

 mals. However, the exceeding difficulty of obtain- 

 ing genetically comparable controls in man makes 

 the study of a lower animal, although vastly differ- 

 ent psychologically, of great interest, since double 

 first cousins — the closest relationship possible for 

 such comparisons — can be used. The first criterion 

 used for judging mental activity has been habit 

 formation in a Watson puzzle box. The habit to 

 be learned consists of a trip around behind the 

 box, breaking an electric circuit and so opening the 

 front door, and returning to the front, entering 

 the box for the reward of food. The data re- 

 corded consist in the times required to open and 

 enter the door of the puzzle box. Each rat has 

 been given 225 trials; 145 rats have been em- 

 ployed in this training. The data, summarized in 

 various ways, have been represented by graphs. 

 Awaiting the results of a second set of training 

 experiments of a different nature, which are be- 

 ing conducted as a cheek on the first method, no 

 general conclusions are given and only provisional 

 conclusions are drawn about the present work. 

 Mole of the Lymphocytes in Besistance to Cancer: 

 James B. Mukphy. (Introduced by Jacques 



LOEB.) 



Experimental Observations on Certain Phenomena 

 of Growth: Thomas B. Osboene and Lafayette 

 B. Mendel. 



The growth impulse, or capacity to grow, can 

 be retained and exercised at periods far beyond 

 the age at which growth ordinarily ceases. In 

 the case of our experimental animals, albino rats, 

 in which increment of body weight ordinarily 

 ceases before the age of 300 days, resumption and 

 completion of growth was readily obtained at an 

 age of more than 550 days. It is now reasonable 

 to ask whether the capacity to grow can ever be 

 lost unless it is exercised. Even after very pro- 

 longed periods of suppression of growth, the ani- 

 mals can subsequently reach the full size character- 

 istic of their species. In this respect there is no 

 impairment of the individual. The satisfactory 

 resumption of growth can be attained not only 

 after stunting by underfeeding, but also after the 

 cessation of growth which results when the diet 

 contains proteins unsuitable for the synthetic 

 processes of growth or is low in protein. Growth 

 in the cases referred to is resumed at a rate nor- 

 mal for the size of the animal at the time. It 

 need not be slow, and frequently it actually ex- 

 ceeds the usual progress. The size or age at which 



the inhibition of growth is effected does not alter 

 the capacity to resume growth. Even when the 

 suppression of growth is attempted for very long 

 periods at a very small size (body weight) the 

 restoration may be adequate when a suitable diet is 

 furnished. The procreative functions are not 

 necessarily lost by prolonged failure to grow be- 

 fore the stage of development at which bleeding 

 is ordinarily possible. The period of growth may 

 be greatly prolonged by inadequacies in the diet, 

 so that growth becomes very slow without being 

 completely inhibited. Though the time of reaching 

 full size is thus greatly delayed, growth, as ex- 

 pressed by suitable body weight, can ultimately 

 be completed even during the course of long-con- 

 tinued retardation. The methods of partially re- 

 tarding or completely suppressing growth are too 

 varied and unlike to permit final answers as yet 

 regarding the outcome of all of the procedures of 

 inhibition for the subsequent welfare of the in- 

 dividual. Our observations apply to the effects 

 upon size and a few other incidental features men- 

 tioned. Although it is doubtful whether the 

 fundamental features will be altered, far reach- 

 ing dogmatic statements are scarcely justifiable 

 until the experiments have been extended to in- 

 clude other factors and animal species. A de- 

 tailed account of the work will appear in an early 

 issue of the Journal of Biological Chemistry. 

 The Calorimeter as an Interpreter of the Life 



Processes: Geaham Ltjsk. 



The measurement of the heat production in fer- 

 mentation of sugar by yeast cells indicates a 

 height of cellular activity, approximating that 

 possible in the cells of mammalian tissue as has 

 been shown by Eubner. The basal heat produc- 

 tion in an adult man is very closely proportional 

 to the surface area, although the age of the 

 organism also plays an important part in this 

 regard. In only a very few conditions of 

 disease is the heat production decidedly changed. 

 Thus, in conditions such as fever and exoph- 

 thalmio goiter there is a largely increased 

 heat production. Fortunately the ingestion of 

 food under these circumstances does not cause a 

 greater heat production than such food would 

 effect if given to a normal man. In all diseased 

 conditions there is no departure from the manner 

 of utilization of the important food stuffs, with 

 the striking exception of diabetes. 

 Ultramicroscopio Study of the Fibrin-gel: W. H. 



Howell. 



The fibrin formed in the coagulation of blood 

 has been described as consisting of a coarse net- 



