14 ’ Papers from the Department of Marine Biology. 
The hyaline globules are greatly increased as the result of thyroidectomy 
(Herring). Cushing states that this increase also follows extirpation of the 
pancreas and that it occurs as the result of section of the infundibular stalk. 
Pars nervosa. This is formed almost entirely of neuroglia fibers with 
neuroglia cells scattered amongst them. Many of the fibers arise from these 
cells, others from the ependyma cells of the infundibulum and of its extension 
into the gland. Between the neuroglia fibers, especially in the neighborhood 
of the stalk, but also in other situations, is to be seen the hyaline and granular 
material already referred to; sometimes in the form of swollen cells, such as 
have been described in connection with the pars intermedia, sometimes as 
amorphous masses; these masses are traceable to the infundibulum, where 
they may be seen passing through the ependyma into the cavity of the ventri- 
cle. There can be little doubt that the physiological activity of extracts of the 
pars nervosa is connected with the presence of this substance within it, since 
extracts of ordinary nervous and neuroglia substance have not the same action. 
Some authors have described nerve-cells within the pars nervosa, but according 
to Herring these do not occur, and there are very few nerve-fibers. The pars 
nervosa is the least vascular portion of the pituitary, its blood-vessels being 
comparatively few in number. 
Besides the cases of the pituitary body and the choroid plexuses we 
may mention the pineal gland and the adrenal bodies as other examples 
of original nerve-tissue that have become modified to form secretory 
tissue. The pineal body originates as an evagination of the dorsal wall 
of the diencephalon. It is composed of epithelial-like cells, trabecule, 
blood-vessels, many neuroglia cells and fibers, and cysts. There are no 
true nervous elements present. In function it is closely related to the 
sexual organs. Tumors involving the pineal body are often accom- 
panied by very early development of sexual maturity with all the sec- 
ondary sexual characters. Feeding pineal glands to very young chicks 
or guinea-pigs accelerates their development. 
The suprarenal capsules consist of two parts, cortex and medulla, or, 
from a broader comparative view, interrenal and adrenal tissues. 
These parts are morphologically distinct, being developed from entirely 
different embryonic anlagen. The cortex is formed from mesoderm 
cells of the genital ridge. The medulla arises from cells which belong 
to the same neuroblast masses that give rise to the nerve-cells of the 
sympathetic ganglia. In fishes these two parts remain separate, but in 
all the higher vertebrates they are united into one organ anatomically. 
In mammals the medulla is centrally located, with the cortex inclosing 
it. The cells of the medulla are characterized by the brown color which 
results after treatment with chromic acid and its salts (chromaphil 
reaction). According to Moore, this reaction is due to the presence of 
adrenaline. The cells are arranged in irregular anastomosing columns 
with large blood-spaces between them. Chromophil granules are 
present which undoubtedly find their way into the blood-spaces directly. 
Besides the chromophil granules, other coarser ones are found, soluble 
in water and alcohol, but not in ether, and staining with difficulty. 
Lipoid and pigment granules may also occur. The tissue is very highly 
