72 HYPOPHYSIS-^OVARY->^OVIPOSITOR II 



of a long continuous strip, which often runs through the 

 entire hypophysis via the glia tissue and terminates in the 

 stalk. It is as if the secretion were pressed out of the cell in a 

 continuous stream passing upwards amongst the glia fibres. 

 Indeed, large acidophil cells can be seen which push out their 

 incretion in the form of threads joined together. In addition, 

 smaller acidophil cells show this abundant production of 

 colloid. The strands sometimes form themselves into spirals 

 in the glia. (Fig. 57). 



In normal animals in spring, we found hypophyses which 

 were almost full of such strands of colloid, and whose stalks 

 had been turned into one compact mass of hyaline secretion. 

 We cannot confirm the statement that these secretions, which 

 are carried through the lobus posterior to the brain, reach the 

 third ventricle. We did not find this hyaline incretion either 

 in the small recessus infundibularis or in the infundibulum. 



From the relatively small quantities passing through the 

 thin stalk at a given moment and available to be absorbed 

 immediately we may conclude that the lobus posterior serves 

 as a reservoir, which may explain the formation of the strings 

 of colloid mentioned above, as a result of internal pressure. 

 The stalk passage, therefore regulates the gradual emission of 

 pituitary hormones in colloid form. We do not yet know 

 which pituitary hormones are secreted as a "colloid", how 

 they enter the main circulation, or reach their destination. 

 The path taken by the substance, however, is as follows (Fig. 

 57). The mass forms itself into drops in the stalk, and moves 

 like a small stream to the front of the hypothalamus between 

 the capillary system referred to above and the large ganglion 

 cells. A smaller stream flows behind the hypothalamus 

 towards the nucleus lateralis tuberis, between those parts of 

 it that run on either side of the recessus infundibularis. Here 

 the colloid spreads through the interstices and the drops 

 become smaller and finally disappear. The region over which 

 the substance spreads extends to a line dorsal to the nucleus 

 lateralis tuberis, but none is observed beyond this level. The 

 hormone, therefore, enters into direct contact with the gang- 

 lion cells, which justifies our calling it a neurocrine secretion. 



