4 



C 0 N A K 1 0 - H T P 0 P U Y S I A L T R A C T . 



have failed to detect in any of the modifications of the part, 

 in Vertebrates, homologous with the pituitary body in Man, 

 evidence of a nervous or glandular part, superadded, for 

 example, to the structure of the lining or mucous membrane 

 of an alimentary canal and to the neural filament endowing 

 such secreting surface with sensibility. Into the materials 

 of the subsequent obhteration, with plethoric consolidation, 

 of the transitory tube neither secerning sacs nor nerve-cells 

 enter. 



Swedenborg, who had extended his studies of the nervous 

 system from Man to Insects, held that " the pineal gland, the 

 infundibulum, and the pituitary gland elaborated the white 

 or lymphatic blood of the brain," and that the pineal body 

 exercised the following more special office : — " The aqueduct 

 under the corpora quadrigemina is a receptacle of the lymph 

 of the third ventricle, which, through a foramen, over which 

 the pineal gland exercises control, pours its liquid stream"*. 

 Henle, like Swedenborg, views the " pineal " as a lymphatic 

 gland. Meynert regards it as " a ganglion originating the 

 tegmentum-cells which are of two sizes." Majendie con- 

 cluded its function to be mechanical; that "the pineal 

 acted as a kind of plug, obstructing the communication be- 

 tween the third and fourth ventricles." Balfour states that 



no satisfactory suggestions have yet been off'ered as to the 

 nature of the pineal gland ;" but, referring to its position 

 external to the skull in Amphibia, he says that it there 

 " forms a mass originally described by Stieda as the ' cerebral 

 gland '"f. 



The researches of which I proceed to communicate results 



* ' The Brain considered Anatomically, Physiologically, and Philoso- 

 phically.' Py Emanuel Swedenborg. 4 vols., 8vo, 1882. Edited by 

 R. L. Tafel, A.M., Ph.D. 



t Op. (it. vol. ii. pp. 257, 258. 



