EFFECTS OF INANITION ON THE BODY AS A WHOLE 77 



defective young proteus 12.6 cm. long. This had possibly developed at the 

 expense of other eggs in the oviduct. Swingle ('18) observed that larvae oiRana 

 pipiens after emergence from the egg capsule may survive inanition for over 

 100 days (doubtless due to the large amount of yolk material present). Podh- 

 radsky ('23) noted shorter periods (up to 32 days) in young tadpoles of Rana 

 fusca. Yung ('78, '83) found that in the later developmental stages malnutrition 

 retards the growth in size and prevents metamorphosis of frog tadpoles until 

 they become sufficiently large. In tadpoles of Rana fusca, however, Barf urth 

 ('86, '86a, '87) discovered that at the time of metamorphosis into frogs starva- 

 tion actually accelerates this process, and thus hastens the development. 

 Wolterstorff ('96) concluded that the result varies according to the stage of the 

 tadpoles used. Although Barfurth's results were denied by Bataillon ('91), 

 Bohn ('04, '04a) noted that while in the earlier larval stages of Rana temporaria 

 the removal of the albuminous capsule (which serves as nutriment) retards 

 growth, it causes metamorphosis into tadpoles at a subnormal size. Kopec 

 ('22, '22a) found that starvation of tadpoles before they are 50 days old retards 

 their development, but after 65 days of age inanition accelerates their 

 metamorphosis. 



Even normally, according to Barfurth, the frog tadpole eats but little during 

 metamorphosis, so fasting merely accelerates the normal process. This was 

 confirmed by Duesberg ('06), who described the histological process of absorp- 

 tion in the tail during metamorphosis (c/. also Morse '18 and Morgulis '23). 

 Pfliiger states that larvae of Alytes obstetricans cease to eat when 8.1 cm. long, 

 and live 5 weeks during which time the extremities are formed at the expense 

 of the tail. According to Chauvin('76) and Kaufman ('18) a similar "physiolog- 

 ical inanition" occurs during the metamorphosis of the Axolotl; and, according 

 to Powers ('03), the metamorphosis of Amblystoma tigrinum is accelerated by 

 starvation. The "physiological inanition" during amphibian metamorphosis 

 recalls the similar conditions found in insects; and also the well-known fasting 

 period of the migrating salmon, during which the sexual products are matured at 

 the expense of the musculature (Valenciennes '48; Siebold '63; Miescher '97; 

 Stone '97; Paton '98; Greene '10, '12; Heitz '18). A similar phenomenon 

 apparently occurs in the male fur-seal (Parker '17) and the gander (Stieve '22), 

 which fast during the reproductive season. 



In mammals, the results on this point have been conflicting. Ver Eecke 

 (01) and Jagerroos ('02) found that the offspring of underfed pregnant animals 

 (rabbits and dogs) develop normally, at the expense of the maternal organism. 

 Similar conclusions were reached for the calf fetus by Tapke ('10) and by 

 Eckles ('16), the latter stating that "All the data indicate that the weight of a 

 calf at birth is not ordinarily influenced by the ration received by the mother 

 during gestation." Zuntz ('19) found that the rat fetus is but slightly modi- 

 fied in weight, even when the fasting mother loses greatly in weight. 



On the other hand, Roloff ('66) stated that underfeeding pregnant animals 

 usually produces fetal maldevelopment. Rudolski ('93) starved pregnant 

 rabbits and a dog, obtaining apparent reduction in the size of the offspring. 

 Similarly positive results were obtained by Paton ('03) for guinea pigs, and by 



