544 PHYSIOLOGY CHAP. 



least touch. These animals may be said to have become 

 haemophilia 



Most frogs at the moment of death exhibit dropsy. Directly 

 the abdomen is opened or the muscles cut through, a colourless or 

 bloody transudate escapes. 



The blood from the heart is more watery ; the erythrocytes are 

 changed in form and colour, and are fewer in number, while the 

 leucocytes are increased. The peritoneum, bladder, stomach, 

 intestine, other abdominal viscera, and the cervical region of the 

 cord are all more or less congested. 



Undoubtedly death results from functional defect of both lobes 

 of the thymus. It invariably occurs, but after an interval which 

 varies from 3 to 4 days. It ensues equally when the two organs 

 are excised at different times, with a longer or shorter interval 

 between the two operations. After the extirpation of one thymus 

 only nothing abnormal appears save a lessened resistance to 

 fatigue. If the second thymus is exposed 15 to 20 days after, it 

 exhibits a certain degree of hypertrophy. Its excision is rapidly 

 followed by the disturbances above described, and death ensues in 

 a short time. 



If the blood or serum from the peritoneal cavity of a frog that 

 is dying from ablation of its thymus glands is injected into a 

 frog that is normal or deprived of one or both thymuses, more or 

 less pronounced disturbances of function will be observed in all, 

 which may produce death even in normal frogs, induce it almost 

 inevitably in frogs with only one thymus, and greatly accelerate 

 it in frogs deprived .of both organs. This fact shows that the 

 tissue fluids of the frog entirely deprived of thymus contain 

 energetically toxic substances, and that the fundamental function 

 of the organ consists in the destruction of these, or in rendering 

 them innocuous. 



Transplantation or grafting of the excised thymus beneath the 

 skin of the same frog or of another deprived of its thymus, does 

 not inhibit the phenomena of auto-intoxication above described. 

 Abelous and Billard, however, observed a temporary abatement of 

 the phenomena of discoloration. On the other hand, subcutaneous 

 injection of extract of calves' thymus (calves' thymus 20 grms., solu- 

 tion of boric acid 100 grms.) in 1 c.c. doses containing 0'02 grrn. of 

 thymus, both in normal frogs and in those which have been partly 

 or wholly deprived of the thymus, produce effects resembling 

 strychnine convulsions, while at the same time cutaneous dis- 

 coloration ceases, and the normal colour of the skin becomes 

 more pronounced. Accordingly there is a true antagonism 

 between the phenomena of thymus deficiency and those produced 

 by injection of the extract of this organ. 



Ver Eecke (1899) also worked on the frog's thymus, coming to 

 conclusions which differed in some respects from those of Abelous 



