492 THE POSTERIOR PITUITARY AND THE NERVOUS SYSTEM. 



Of course, this applies to both pituitary bodies, but we 

 have shown that the anterior pituitary as the source of the 

 nervous impulses transmitted through the splanchnics was in 

 reality a nerve-center; and we have further referred to the 

 fact that the pituitary as a whole has long been associated 

 with the nervous system by anatomists, and particularly with 

 the "sympathetic" system by Bourgery and Hirschfeld. That 

 the investigations of Andriezen should have borne but little 

 fruit, so far, is probably accounted for by his statement that 

 "variations in weight bring it under the Darwinian law of 

 panmixia; if so, the indication being, what study of lower 

 vertebrates shows, namely: that it has probably passed the 

 acme of its activity and in man is functioning less vigorously." 



We must express our belief, however, that, when man is 

 in question, cessation of natural selection may not always mean 

 that an organ has become useless, but instead that it has 

 reached the acme of perfection. Loss of functional vigor may 

 denote, in this connection, what it denotes in the human hand 

 as compared to that of the gorilla: i.e., gain in functional 

 precision and delicacy. 



In the embryo, the posterior pituitary body opens directly 

 into the third ventricle through the infundibulum. If during 

 uterine existence "the whole life-achievement of myriads of 

 generations of living things" is represented, the phylogenetic 

 history of this organ should show traces of its ultimate func- 

 tions. Andriezen found that in the amphioxus its analogue 

 is represented by "a subneural glandular organ, a duct lined 

 by ciliated epithelium which affords a communication between 

 the buccal and neural cavities, and a group of nerve-cells 

 around and at the back of the upper opening where the duct 

 widens into the ventricular cavity." We have here the main 

 primitive structures of the pituitary in man. 



Referring to Andriezen's investigations, Berkley 6 says: 

 "He has farther shown that particles of carmine, suspended 

 in the water surrounding the animals, will be taken up with 

 the water passing through the infundibular duct and carried 

 by ciliary action into the ventricle, and thence into the central 



Berkley: Brain, Winter, 1894. 



