46 INANITION AND MALNUTRITION 



corresponding "parenchyma." In starvation, the body wall is reduced to about 

 0.04 mm. in thickness; including 0.02 mm. for the epithelium, 0.01 for the 

 "parenchyma" and outer muscle, and 0.01 mm. for the remainder. 



The cutaneous epithelial cells become lower, but the gland-cells may retain 

 their original height. The reduction in size of the muscular and "parenchyma" 

 layers is chiefly at the expense of the interstitial gelatinous substance, but most 

 of the " Parenchymzellen und Bindegewebeselemente" also disappear. The 

 muscles are also greatly atrophied; the individual fibers may be reduced to one- 

 half in length and diameter. The depigmentation of the body is striking, the pig- 

 ment cells undergoing degeneration and resorption in various parts of the body 

 (including intestine, brain and eyes). Resorption is accomplished through 

 phagocytosis by the wandering cells, which transport the material chiefly 

 in pigment form to regions where most needed (Fig. 15). 



The intestine in Linens is decreased about one-third in thickness and two- 

 thirds in number of epithelial cells counted in a cross section. In many places, 

 especially in the hindgut, a degenerative involution occurs, particularly involving 

 the folds projecting into the lumen (Fig. 15). The epithelial cells form extensive 

 degenerative syncytial areas, within which occur occasional islets with cells of 

 embryonal appearance. These may be able to regenerate the epithelium upon 

 refeeding. The eyes degenerate and disintegrate, as described for the planarians. 

 The reproductive system undergoes a partial reduction. "Sowohl in den 

 Hoden wie auch in den Ovarien unterliegen gewisse Abschnitte des Keimepithels 

 einem vollstandigen Zerfalle under Mitwirkung von Wanderzellen . . . 

 Gewisse Abschnitte der Gonaden bleiben aber bestehen und hier bilden sich die 

 Geschlechtsprodukte aus . . . Die Gonodukte unterlogen keiner Reduction, 

 sogar in sehr spaten Inanitionsstadien." The nervous system is very resistant; 

 an apparent skrinkage in volume is due to atrophy of the connective tissue, the 

 nervous elements remaining intact. There is likewise little or no change in the 

 proboscis, nephridia, vessels, etc. 



In general, therefore, there is in Linens a remarkable difference among the 

 various tissues and organs as to the time and extent of their reduction. A 

 decrease in both number and size of cells is involved. In some cases the nucleus 

 is more resistant than the cytoplasm, but in general the "Kernplasmarelation" 

 is not much changed. In certain regions progressive, regenerative changes may 

 occur among regressive, degenerative changes. The changes in Linens during 

 inanition and in regeneration of the body are naturally similar, since the regen- 

 erating organism takes no food and structures are regenerated at the expense of 

 the remainder of the organism. 



NEMATELMINTHES 



Among the roundworms, but few observations on the effects of inanition are 

 available. Maupas ('00) noted that in the hermaphroditic nematodes mal- 

 nutrition reduces the number of ova, but does not affect the sex. In Ascaris, 

 Weinland observed that the duration of starvation is greatest (seven to nine 

 days) in fluid saturated with carbon dioxide. There is a marked decrease in the 

 (normally very high) glycogen content. Ono ('20) studied the effect of starva- 



