Effects of Grafting and Feeding with Pituitary 105 



animal's own gland, for he states that he was able to observe a temporary 

 increase of growth of animals in which he implanted an extra pituitary as 

 compared with controls. Other methods which might be expected to pro- 

 duce hyperpituitarism consist (1) in the addition of pituitary substance to 

 the food, (2) in the subcutaneous injection of extracts at regular intervals 

 during a prolonged period of time. The second method has been stated by 

 some observers to produce a retardation of growth of the skeleton and of 

 the body generally a result exactly the contrary to what would be ex- 

 pected if, as there seems no reason to doubt, the symptoms of acromegaly, 

 presently to be described, are due to hypertrophy of the gland, especially 

 of the anterior part. A series of experiments by the first method which 

 were carried out by me upon white rats and extended over several months 

 showed no constant effect in facilitating the growth of young animals 

 although there was no sign of retardation. R. Wulzen records, on the 



o o 



contrary, a retardation of growth in chicks when pituitary was added to 

 the food, the effect being more marked in males than in females. But 



O 



the most remarkable result of feeding with pituitary substance (anterior 

 lobe) is that described by L. N. Clark (Journ. Biol. CJtem., Oct. 1915), 

 who experimented on laying hens. In the first experiment, 35 White 

 Leghorn hens, as well as 2 cockerels of the same breed with which they 

 were mated, each received daily during eight days the equivalent of 20 mg. 

 of fresh pituitary substance in addition to their usual food. By the fifth 

 day the egg production of the batch was raised from an average of 18 per 

 diem to 33 ; the beneficial effect, although diminishing, was maintained for 

 several days after the pituitary had been taken off. And not only was 

 the output of eggs largely increased as compared with the controls, but 

 the fertility of the eggs and the hatching out of the chicks was extra- 

 ordinarily enhanced. In order to test the matter further, a second experi- 

 ment was performed with as many as 655 one-year-old White Leghorn 

 hens (kept without males), the same dose as before being administered to 

 each hen during four days. The average daily number of eggs laid by 

 the batch during the four days preceding the pituitary feeding was 233, 

 during the four days succeeding the administration, 352 ! These experi- 

 ments were made at a time of year when the egg production of the hens 

 was tending to diminish rather than to increase. 



