EXPERIMENTS WITH CYTOST 107 



leads to autolysis. Whichever explanation is correct, 

 the fact remains that the histological examination of 

 the body tissues disclosed marked autolysis of the 

 tissue cells. 



This fact is but the expression of a general rule that 

 nutritive disturbances which hinder the normal course 

 of metabolism always result in the degeneration of an 

 animal's tissues. This is seen in the various forms of 

 illness, which are of common occurrence in captive 

 wild animals, and will be discussed more fully in 

 Chapter IX. 



The reader is probably familiar with the well 

 known fact that disuse of a tissue, such as a muscle, 

 leads to atrophy and cellular degeneration. With this 

 fact in mind, the writer conducted the following ex- 

 periments. (Turck, 1906.) The experimental ani- 

 mals were placed in small sterilized cages which pre- 

 vented them from moving about. Ninety-six guinea 

 pigs and thirty-six rabbits were caged in this fashion 

 and given a normal diet. During the first few months 

 the animals gained in weight, due to deficient exercise. 

 Later, although supplied with sufficient food, they 

 became emaciated. At autopsy, general tissue de- 

 generation and autolysis were found, as well as peptic 

 ulcers in some cases. During the course of these ex- 

 periments, routine blood examinations were made and 

 those animals showing any evidence of infection were 

 immediately discarded. At the expiration of nine 

 months but six guinea pigs remained alive. At au- 

 topsy general tissue degeneration and autolysis were 

 found in all cases, as well as several instances of pep- 

 tic ulcers. 



More than three hundred years ago Borelli demon- 



