4 ARON. 



the requirement for maintenance of young dogs as equal to the caloric 

 intake during periods in which the weight of these dogs neither increased 

 nor decreased. 



Will growth, suppressed by the necessary restriction in diet, cease 

 entirely for an indefinite leng-fh of time? What becomes of an animal, 

 suffering such a suspension of growth, when it is given an abundant 

 food supply? 



Eubner '^ states as follows in regard to these questions : 



If the cells of a young animal are insufficiently nourished, the growth does 

 not proceed. There is also no decrease of the energy metabolism (under which 

 circumstances a decrease of the body temperature could not be avoided), but 

 growth stops, without there being a loss of the "tendency to grow" in the near 

 future. He bases this idea on experiments performed by 0. Kellner with the 

 silkM'orm and upon the work of Quetelet, who found the individuals of the work- 

 ing class to be smaller in stature than those of the better classes. 



I shall here quote from the investigation of Kellogg and Bell ^ on the 

 influence of diminished nourishment on silkworms {Bombyx mori) . 



These authors state that "there exists a very definite and constant relation 

 between amount of food and size as indicated by weight, the starveling individuals 

 being consistently smaller than the well-nourished, the lingering effects of this 

 dwarfing being handed down even unto the third generation, although the progeny 

 of the famine generation be fed the optimiun amount of food. In case the dimin- 

 ished nourishment is imposed upon three or even two successive generations there 

 is produced a diminutive, but still fertile, race of Lilliputian silkworms whose 

 moths, as regards wing expanse, might join the ranks of the micro-Lepidoptera 

 almost unremarked. 



"An abnormal extension of the time needed for the metamorphosis follows 

 upon a reduction of the food supply." 



After my experiments were nearly finished and reported in part 

 at the Far Eastern Association for Tropical Medicine in March,^ 1910, 

 there came to my attention, through the courtesy of Geheimrat Zuntz, 

 a paper by H. F. Waters," which deals with a problem similar to mine, 

 but considered principally from the standpoint of animal husbandry. 



This author reports on experiments on cattle which were fed with widely dif- 

 ferent quantities of food, in order to cause in some a normal gain in live weight 

 (full fed) ; in others a fair growth but without allowing fat to be stored up 

 (moderately fed) ; in still others only a slight gain in live weight (retarded 

 development). In another group the feeding was so conducted as to allow of 

 no increase in live weight (maintenance), and in a last group the animals were 

 fed so as to lose in live weight ( submaintenance ) . Waters has carefully studied 

 the build of these animals, their size, and the size of their different parts. His 

 results will be discussed in detail later in connection with my own. 



'Arch. Eyg. (1908), 66, 1-208; Kraft und Stoff im Haushalte der Natur, 

 Leipzig (1909), 116-117. 



'Science, (1903), 18, 744, 746. 



^Berl. klin. Wchnschr. (1910), 993. 



° The influence of nutrition upon the animal form. XXX. Meeting of Society 

 for the Promotion of Agricultural Science. 



