The Comparative Pliysiolof^y of the Pituitary Body 



265 



the effects of the injection of 5 c.c. of an extract of anterior lobe in Ringer's 

 solution into the blood-vessels of a cat. The anterior lobe of the fowl's 

 pituitary does not, therefore, contain any active principles exerting an 

 immediate physiological effect upon blood -pressure, kidney volume, or 

 secretion of urine. In this respect it resembles the anterior lobe of the 

 mammalian pituitary body. 



Posterior Lobe. 



The posterior lobe is readily separated from the anterior, and yields 

 a greyish gelatinous material which dissolves to a certain extent in 

 Ringer's solution. When boiled, filtered, and injected intra venouslj^ such 

 extracts produce innnediate and well-marked effects. The blood-pressure 

 begins to rise soon after the injection, the heart beats more rapidly, and 



Fig. 1. — Ett'ect of injection into jugular vein of a cat of 5 c.c. of an extract of anterior lobe 

 of the fowl's pituitary in Ringer's fluid. 



a, blood-pressure ; k, kidney oncograph ; u, urine secretion (drops) ; t, time in 5 sec. intervals ; »■, signal. 

 In this and subseguent tracings the line t represents the zero of blood-pressure. 



the large respiratory waves, when present, are abolished or very much 

 diminished in size. The rise in blood-pressure occurs slowly and attains its 

 maximum about two minutes after the injection. The rise is not a large one, 

 but continues for some time and then gradually falls to normal. The respira- 

 tory movements, in spite of the continued supply of air containing the anes- 

 thetic from the air-pump, are sometimes affected. Soon after injection the 

 respiration is increased or inhibited for a short time, and then resumed as 

 before. The kidney volume shows a slight initial increase, followed by a 

 slow and gradual expansion, which, after a 5 c.c. dose (8 glands in 40 c.c. 

 Ringer), attains its maximum in about fifteen minutes, and then falls gradu- 

 ally to what it was before the injection, the whole phase lasting about half 

 an hour. The secretion of the urine increases with the expansion of the 

 kidney, a latent period of one to two minutes usually elapsing before the 

 increase begins. 



The increase of urine is ver}^ pronounced. In the example of which 

 fig. 2 is a tracing, the increase is from 12 drops in five minutes before the 



