348 Kojima 



Operative Procedures. 



The operations for removal of portions of thyroid and parathyroid 

 have been described in a former paper, and the description need not be 

 recapitulated. 



Microscopic Examination of the removed and remaining 



Thyroid and Parathyroids. 



Thyroid. — The removed thyroids are of normal appearance, and the 

 description which has just been given will apply to them completely. 



Thyroid Remainders. — The size of these is obviously increased 



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_jiK. __ 



Fjq, 1. — Section of normal thyroid of dog (male) removed by operation, fixed 

 with 10 per cent, formol and embedded in celloidin. Microjjhotograph ; 

 magnified 75 diameters H*matoxylin-eosin preparation. 



The vesicles are full of colloid, which is stained faintly by the hsema- 

 toxylin-eosin. The lining epithelium cells are cubical. 



if calculated from the size of the part removed. For although only 

 about one-third of each lobe was left at the operation, what is now present 

 would certainly be equivalent in size to at least one-half. 



Even the low power shows striking changes in the structure (lig. 2). 

 The section appears like a number of tubules cut irregularly rather than 

 a collection of vesicles. The size and shape of these tubules vary con- 

 siderably. Generally speaking they are irregular, some of them branching. 

 Many are empty, but some contain a small amount of a colloid which stains 

 faintly red by eosin and has a much thinner appearance than normal. The 

 columnar epithelium cells which line the vesicles are much higher than in 

 the removed portions. Their cytoplasm is less compact, and contains small 

 vacuoles. The granules within it are coarser than normal. Most of the 

 nuclei are round. They vary in size from 3"7f(. to 62/x, and contain 



