METABOLISM 



307 



Figure ly^. Very diagrammatic 

 sketch of the pituitary gland of a 

 Fin Whale, seen from the left. 

 The anterior lobe is drawn in 

 longitudinal section to show that 

 the pars tuberalis runs into it. 

 S = stalk; Pt = pars tuber- 

 alis ; Po = posterior lobe ; A = 

 anterior lobe; D = dura mater 

 with septum between anterior 

 and posterior lobes. 



mater of the brain. In this way, the two lobes are completely separated 

 from each other, and there is no special pars intermedia connecting them, 

 as there is in most other mammals. Prof. Gaillard of Leyden University 

 has shown experimentally that, in all vertebrates, the special tissue of the 

 intermediate lobe can only be formed when the two lobes are in direct 

 contact with each other and not otherwise. The fact that a pars inter- 

 media is also lacking in so ill-assorted a collection of animals as sea-cows, 

 elephants, armadillos and birds, is an indication of how difficult it is to 

 interpret this phenomenon. We shall therefore not attempt any further 

 discussion of it, but merely mention that intermedine, the hormone 

 secreted by the intermediate lobe of those vertebrates which have one, is 

 secreted by the anterior lobe in Cetaceans. 



The two lobes of the Cetacean pituitary were found to yield the same 

 hormones as those of other mammals. The first scientist to isolate and 

 prepare these hormones was A. P. Jacobsen, ship's surgeon on the Nor- 

 wegian factory ship Kosmos, on which he sailed to the Antarctic and 

 collected specimens of Cetacean endocrine glands in 1935. On his return, 

 he did research work at Oslo University under the auspices of the Whaling 

 Fund and a private chocolate company which was interested in whale 

 hormones industrially. Jacobsen and many scientists after him succeeded in 

 proving that certain hormones which affect uterine contractions, blood 

 pressure and the excretion of urine can be obtained in adequate quantities 



