EFFECTS OF INANITION ON THE BODY AS A WHOLE 89 



tinued growth in some parts at the expense of other during inanition has but 

 recently been recognized as a general phenomenon. Although apparently (in 

 vertebrates) first observed in the human species, we may first consider the 

 phenomena as found in lower animals. 



Waters ('08, '09), at the Missouri Agricultural Experiment Station, held 

 15 young (yearling) steers at maintenance by underfeeding for several months 

 and noted some curious changes. The skeleton continued to grow, resulting in 

 progressive increase in height and length, apparently at the expense of the adi- 

 pose and muscular tissues. Although remaining constant in weight, the body 

 underwent various changes in proportions, the head becoming larger and the 

 thorax elongated dorsoventrally. About the same time, Lassabliere noted in 3 

 malnourished puppies a dissociation of growth in length and weight, similar to 

 that found by Variot in human infants (to be mentioned later). Aron ('10, 

 'n) likewise noted that puppies underfed so as to maintain nearly constant body 

 weight continued to increase in length and height on account of persistent 

 skeletal growth. Other changes noted will be mentioned later. A similar 

 persistent growth of the skeleton at the expense of the remainder of the body 

 was also noted by Falke ('10) in underfed calves, by Aron ('13, '13a) in underfed 

 rats, and by Mendel and Judson ('16) (judging by ash-content) in underfed mice; 

 although Tschirwinsky ('10) had obtained negative results in undernourished 

 lambs. 



The first complete and systematic analysis of the relative weight changes in 

 the various parts of the growing body as a result of underfeeding was made 

 by Jackson ('15a) in the albino rat, beginning at three weeks of age or later. 

 Although there was an increase in body length, and especially in tail length, 

 as a result of persistent skeletal growth, the changes in general body proportions 

 otherwise were not marked. There was apparently a slight increase in the head 

 weight, counterbalanced by a similar decrease in the trunk and extremities 

 (Fig. 39). Judson ('16), Thompson and Mendel ('18) likewise noted changes 

 in the proportions of underfed white mice, the head becoming relatively enlarged 

 and the tail elongated. The various abnormalities of growth on insufficient 

 or inadequate diet were reviewed by Mendel ('17). 



The results of Jackson ('15a) upon albino rats underfed beginning at 3 

 weeks (age of weaning) or later were confirmed by Stewart ('16). In experi- 

 ments beginning on the newborn rats, however, Stewart ('18, '19) found some- 

 what different results. In this case, in addition to the increase in body and tail 

 length, there was a marked increase (45 per cent) in the head weight, while the 

 body weight decreased slightly (4 per cent) . The differences in other organs were 

 even more strongly marked, as will appear later. 



In albino rat fetuses retarded in growth by underfeeding the mother during 

 the latter half of pregnancy, Barry ('20, '21) found a slight increase in the weight 

 of the head and limbs, with a corresponding decrease in the trunk. The body 

 length and tail length were also nearly normal, the skeletal growth being much 

 less pronounced than that found by Jackson and Stewart during postnatal 

 inanition. The results therefore appear to differ materially according to the 

 age at which the inanition occurs. j 



