

THE THYKOID GLAND AND ITS DISEASES 



217 





lumen and remote from the basement membrane. Goetsch (a) has found 

 that they constitute a valuable criterion of the activity of the epithelium. 



Cell Inclusions. Glycogen and crystalloids are of comparatively rare 

 occurrence, but when they do occur they can be easily studied in the 

 fresh condition. It may be remarked that the crystalloids sometimes 

 resemble quite closely those occurring in the interstitial cells of the 

 testis. Both fat and glycogen are said, as is the case in most tissues, to 

 be more abundant in old subjects. Cells undergoing mitotic division 

 are rare. 



Eeticular Apparatus. By ap- 

 propriate methods of fixation and 

 staining rather more can be made 

 out of the intimate structure of 

 the cells. Using Golgi's arsenious 

 acid method, Negri has described 

 the presence of a well formed 

 reticular apparatus in these cells, 

 in the form of a circumscribed net- 

 work which blackens with silver. 

 It is located between the nucleus 

 and the lumen of the follicle. I 

 have confirmed and extended 

 NegrFs observations by using 

 CajaPs latest uranium and silver 

 nitrate method, which gives prep- 

 arations as illustrated in Fig. 7. 

 Unfortunately, the evidence is not 

 conclusive that a similar network 

 occurs in the living condition, so 

 that we are unable as yet to in- 

 terpret these findings. If it does occur, and if Bensley's hypothesis is cor- 

 rect, that it is the homologue in the animal cell of the vacuole in plant cells, 

 its study should afford valuable information with respect to the condition 

 of the epithelium. Iron hematoxylin preparations show that the cen- 

 trosome is located in the distal pole of the cell, that is to say, in that part of 

 the cell remote from the basement membrane and near to the lumen. 

 Secretion antecedents within the cells have been discovered by 

 Bensley (&) through the elaboration of a new method of technic, consisting 

 of fixation in formalin-Zenker and of staining with Brazilin and water 

 blue. They are seen in the form of vacuoles, which occur exclusively 

 in the proximal part of the cell near the perifollicular blood vessels. 

 The vacuoles contain a dilute solution similar in its properties to the 

 intrafollicular colloid. This discovery may go far toward clarifying 

 our whole conception of the structure of the thyroid gland. 



Fig. 7. Section of a pigeon's thyroid pre- 

 pared by CajaPs uranium and silver nitrate 

 method in order to demonstrate the reticu- 

 lar apparatus which is here seen in the 

 form of a blackened network between the 

 nuclei and follicular lumen. 



