THE PITUITARY 365 



very considerably according to its age. Adult dogs and cats 

 will not survive more than two or three days ; young animals 

 may live as many weeks. 



2. Partial extirpation of the pituitary body (if a small part of 

 the anterior lobe be left behind) gives rise to disturbances in 

 growth and metabolism already described, and these may be 

 induced in young animals by deficiency of anterior lobe only. 



3. The effects upon the genital organs may be due to de- 

 ficiency of the pars intermedia, and the preponderance of 

 evidence is that the polyuria and disturbance of carbohydrate 

 metabolism (tolerance) are due to deficiency of this part as well. 



4. It seems possible that removal of the nervous portion 

 proper would be without any serious effects. This operation 

 can, however, scarcely be carried out without damage to the 

 pars intermedia, and this damage brings with it the metabolic 

 disturbances just referred to. 



It is interesting to note that, just as in the case of the adrenal 

 body, so we have in the pituitary two main portions, one of 

 them glandular, the other nervous. In the case of both organs, 

 the physiologically active substances are found in the nervous 

 portion (neurohypophysis, adrenal chromaphil tissue), while 

 the glandular portion seems to be that w^hich is essential to life. 



The above summary represents the views of the majority of 

 those who have devoted themselves to the subject of pituitary 

 extirpation. But it is somewhat disconcerting to find careful 

 observers who express themselves in such a sceptical vein as do 

 Camus and Roussy. These authors believe that the polyuria 

 which occurs on extirpation of the pituitary is not due to the 

 removal of this organ, but to a lesion of the opto -peduncular 

 region at the base of the brain. This region lies at the level of 

 the grey substance of the tuber cinereum in the vicinity of the 

 infundibulum. This zone seems to play some part in the 

 mechanism of water retention in the organism. Atrophy of 

 the genital organs and the " adiposo-genital syndrome " are 

 likewise due less to any hypophyseal lesion than to trouble at 

 some point in the base of the brain. The same applies to the 

 changes in tolerance to carbohydrates and the appearance of 

 alimentary glycosuria. These experiments, if the results are 

 confirmed, will necessitate a reconsideration of our whole attitude 

 in relation to the pituitary body. 



