2 6 
pressure, be made to exude from the cell in refractive 
globules. In specimens hardened in alcohol, this clear 
secretion appears as a granular mass, occupying the 
greater portion of the cell. It stains faintly with 
haematein, and shows under high powers a coarse 
reticulum and isolated globules, an appearance pro¬ 
bably due to the precipitation or coagulation of the 
secretion by the alcohol. 
The protoplasm of the cell occupies, in the fully- 
matured gland, only the extreme periphery, and the 
nucleus, which is much degenerated, is pushed to the 
outer portion of the cell, and usually lies in the angular 
interval left at the base of two or more contiguous 
cells. 
The Clear or Colloid-like Type .—Of this type 
there is but a single acinus upon either side, which 
usually lies between the two acini of granular type 
(Fig. 46). 
In the fresh gland the cell outlines are not so 
distinct as in the granular type, and the secretion, 
when extended by pressure, is much less refractive. 
In alcohol-hardened specimens, the acinar cells contain 
a large mass of clear, homogeneous secretion which, 
as in the last-mentioned type, fills almost the entire 
cell, and pushes the protoplasm and nucleus to the 
periphery. 
In the clear type, however, the protoplasm is 
always in greater amount than is the case with the 
granular type, and the nucleus never becomes so 
greatly degenerated. The clear, homogeneous secre¬ 
tion stains readily with haematein, and may even stain 
quite deeply. With Heidenhain’s haematoxylin it 
frequently becomes almost black. It resembles very 
much in appearance colloid substance as it is seen in 
the mammalian thyroid. 
