396 INANITION AND MALNUTRITION 



subnormal in weight at the end of one-half week; but above weight 43.2, 44.5, 

 and 27.9 per cent, respectively, after 1, 2 and 4 weeks of refeeding. Thereafter 

 they appeared nearly normal in weight. In rats underfed from birth to 3, 6 

 or 10 weeks, and then refed to 25, 50 or 75 g. in body weight, Jackson and 

 Stewart ('19) found the ovaries somewhat variable in weight, but definitely 

 (20-29 P er cent) subnormal in those which had been subjected to the longer 

 underfeeding periods (Table 7). In another series, underfed from birth to 3-10 

 weeks, or from 3 weeks for long periods, and then fully refed to the maximum 

 attainable size, Jackson and Stewart ('20) found the ovaries always atrophic, 

 averaging 32-61.5 per cent subnormal in the various groups (Table 8). 



Some allowance must be made for the great variability in the weight of the 

 ovary (on account of the changes during the estrus cycle), but the evidence 

 clearly indicates that severe or prolonged underfeeding causes a profound 

 atrophy of the ovary, which is sufficient to account for the marked degree of 

 sterility usually found in such animals (Jackson and Stewart '18, '20). King 

 ('18) likewise noted that malnourished female rats are usually sterile, but may 

 regain their fertility when the general nutrition is improved. Osborne and 

 Mendel ('17) found that in females stunted by underfeeding to the age of 6-17 

 months (body weight 90-108 g.), and then fully refed, the menopause is post- 

 poned long beyond the normal age and apparently vigorous young may be 

 produced. 



Swingle C18) noted that in frog larvae {Rana pipiens) almost completely 

 starved for over 100 days from the emergence from the egg capsule the develop- 

 ment of the gonads and germ cells is almost entirely inhibited. In older 

 (yearling) larvae of Rana catesbiana, the development of the gonads proceeded 

 during starvation for 5 months and 10 days, so their microscopic structure 

 appeared identical in test and control larvae, in spite of marked atrophy of the 

 body as a whole and of the corpora adiposa. 



Stieve ('18) found that in hens the ovarian activity and egg-laying are soon 

 interrupted by imprisonment or inanition. Histologically the ovarian follicles 

 were shown to undergo more or less rapid atresia, and the large ova with their 

 yolk are resorbed in 5-10 days. Upon refeeding, new follicles and ova 

 develop, but not until the yolk has been completely resorbed from the follicles 

 in process of atresia. Stieve concluded that the germ cells are much more 

 susceptible to environmental influences than is usually believed. 



Stieve ('21) made further extensive investigation upon tritons (chiefly 

 Triton vulgaris), and concluded: 



"Zusammenfassend lasst sich sagen, dass Hunger und sparliche Fiitterung 

 vor der Brunst nicht schadet, sofern zu Beginn der Fortpflanzungszeit reichliche 

 Nahrungszufuhr erfolgt. Wahrend der Brunst selbst bedingt Hunger den . 

 Stillstand der Eiablage, jedoch nicht plotzlich, sondern erst nach einigen Tagen; 

 bei sparlicher Ernahrung ist die Zahl der abgelegten Eier gering. Sehr reich- 

 liche Fiitterung vor der Brunst verhindert die Fortpflanzungstatigkeit, wohin- 

 gegen sie wahrend der Laichzeit die Eiablage steigert. Bei sparlicher Ernah- 

 rung und beim Hunger wird stets zuerst der Fettkorper aufgebraucht, erst 

 dann lassen sich schwerere Veranderungen am Eierstock nachweisen. Bei 



