734 J. F. GUDERNATSCH 



The structure of the colloid varies with the species and is the 

 same through all the follicles. A peifectly homogeneous colloid 

 exists in cases, in others it is granular, and finally in some fish it 

 is of a lumpy consistency. The consistency of the colloid also 

 varies with age, in old animals being rather cloudy in appearance 

 and evidently very brittle after fixation. Occasionally the outer 

 portion of the colloidal mass stains a trifle lighter which is the 

 only indication of a concentric structure. This alone, however 

 does not argue for the view that the colloid is a by-product of 

 the active thyreoid, which collects and remains in the follicle. 

 Langendorff first presented such an idea which of course called 

 forth great opposition. 



Blood corpuscles are occasionally found in the Teleost thyre- 

 oid and sometimes completely fill the lumen of the follicles or 

 may be scattered or bunched together. Blood is also occasion- 

 ally found in the human follicles. Baber was no doubt mistaken 

 when he spoke of a real flow of blood into the follicles, as such 

 does not occur. How the corpuscles enter the follicles is not 

 known, though it is probable that somewhere, by pressure or 

 tension, the delicate wall of a capillary lying next to the epithe- 

 lium is ruptured and the corpuscles find their way into the fol- 

 licular lumen through an injured wall. Hiirthle believes the 

 'melting' of the epithelium responsible, when it occurs at a place 

 where capillaries lie deeply imbedded. It is evident that when- 

 ever blood corpuscles do enter the lumen they are destroyed, 

 and they may be seen in all stages of disintegration until finally 

 pyknotic shadows of nuclei alone exist with no indications of 

 their cell bodies. The scattered corpuscles lie within the colloid, 

 which must therefore, be rather liquid. The content of the 

 follicles has a haemolytic property without being itself of 

 haematogenic (Baber) origin. 



Cells from the follicular epithelium also form a part of the 

 follicle content. These are pushed off either singly or several 

 together into the lumen and there destroyed; they also lie within 

 , the colloid. Two kinds of cells aie distinguished, those with a 

 small body and dense cytoplasm, resembling somewhat epithelial 

 cells of the ordinary type and those with a swollen body, and 



