338 ELEMENTS OF HISTOLOGY. [Chap. XLIII. 



cavity. Branches of olfactory nerve-fibres also pass 

 into the median wall, and behave in exactly the same 

 manner as in the olfactory region. Numerous serous 

 glands belonging chiefly to the upper and lower 

 wall open into the cavity of the organ of Jacobson. 



In the lateral wall there is in many instances a 

 plexus of veins, extending in a longitudinal direction, 

 and between the vessels are bundles of non-striped 

 muscular tissue, thus constituting a sort of cavernous 

 tissue. 



CHAPTER XLIII. 



THE DUCTLESS GLANDS. 



496. I. The hypophysis cerebri. The upper 

 or smaller lobe belongs to the central nervous system. 

 The lower or larger lobe is surrounded by a fibrous 

 capsule, which sends numerous minute septa into the 

 interior. These split up into numerous trabeculse of 

 fibrous tissue, which, by dividing and re-uniting, form 

 a dense plexus, with smaller and larger, spherical or ob- 

 long, or even cylindrical spaces the alveoli. In these 

 lie spherical or oblong masses of epithelial cells. These 

 epithelial cells are columnar, pyramidal, or polyhedral, 

 each with an oval or spherical nucleus. Between the 

 epithelial cells of the same group are found here and 

 there small branched or spindle-shaped cells, with a 

 small flattened nucleus. In some of the groups or 

 alveoli of epithelial cells is a cavity, a sort of lumen, 

 filled with a homogeneous gelatinous substance. 



The interalveolar connective tissue contains a 

 network of capillaries. Between the alveoli and the 

 interalveolar tissue there are lymph sinuses, like those 

 around the alveoli of other glands e.g., the salivary 

 glands. 



