82 The Endocrine Organs 



duodenal extract indubitably causes the appearance of the pituitary 





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Fig. 53. — Section of pars intermedia of ox pituitary where it abuts on pars nervosa. 

 Two colloid vesicles are seen amongst the cells. Magnified 200 diameters. 



p IG 54, — Section of cat's pituitary, showing on the left a thickened portion of pars inter- 

 media, with several vesicles amongst its cells, and on the right pars nervosa with 

 two hyaline masses amongst its fibres. The sharp edge of the pars intermedia on 

 the left forms part of the boundary of the intraglandular cleft ; the free edge on the 

 right of the pars nervosa is part of the boundary of the extension of the third ventricle 

 into the gland. 



autacoids in the cerebro-spinal fluid ; a fact which makes it evident that 

 they must normally be passed to some degree into that fluid. The hyaline 



