SECT. 1 80.] GLAND-VESICLES OF THE THYROID. 



393 



Fig. 102. 



Some gland-vesicles from the thyroid gland of a 

 child ; magnified 250 times, a. Areolar tissue between 

 the same. 6. Membrane of the vesicles, c. Their 

 epithelium. 



these cells is filled with a clear, somewhat yellowish viscid fluid, 

 whose behaviour with alcohol and nitric acid, or on the application 

 of heat, clearly shows the 

 presence of a large quantity 

 of albumen. Such, then, 

 are the contents of the 

 gland-vesicles in the healthy 

 human thyroid, particularly 

 in that of children ; but let 

 the organ be but a little 

 altered, and uumerous other 

 conditions make their ap- 

 pearance. Very frequently 

 there is found, instead of a 

 regular epithelium, nothing 

 but a fluid mingled with 

 small clear and dark gra- 

 nules and free nuclei. 

 However, it is very possible 

 this peculiarity of the contents is the result of post mortem change, 

 rather than of disease ; for a transitional state may be observed 

 where epithelial cells, bleached and half dissolved, are found free 

 in the interior of the vesicles. On the other hand, we meet with 

 a condition which is, beyond doubt, pathological, consisting in the 

 transformation of the thyroid and its vesicles into ' colloid.' Early 

 stages of this degeneration, however, are so common, that many 

 writers have described 

 it among the physio- 

 logical appearances. 

 The change consists in 

 the development of 

 colloid substance in 

 the interior of enlarged 

 gland -vesicles. The 

 colloid itself forms 

 transparent amorphous 

 masses, softish and vel- 

 lowish, like the same 

 substance met with 

 elsewhere. In the 

 slighter grades of this 

 alteration, the vesicles 



Fig. 1G3. 



Acini of the thyroid with colloid substance, 

 times. 



Magnified 50 



