THE LYMPH AND THE CHYLE. 11 



with abundantly in the thymus gland of still-born children, and 

 also in the thyroid body and supra-renal capsule; in the 

 last, indeed, almost every cell is nucleated. 



On this supposed essential structural distinction between 

 the true glands which are furnished with excretory ducts, 

 and those anomalous ones which are destitute of such ducts, 

 Mr. Simon founds some general deductions. 



It is known that the functions performed by the glands 

 without ducts are of a periodic and temporary character, while 

 those discharged by the true glands are of a permanent and 

 constant nature. 



It is also considered by some physiologists that the nucleus 

 of every nucleated cell is the only true and necessary secre- 

 ting structure. 



These views of the nature of the functions performed by 

 the anomalous glands, and of the importance of the nucleus, 

 being adopted by Mr. Simon, he thence draws the inference 

 that the cytoblastic condition of the cells of the thyroid, 

 thymus, and other analogous glands, is precisely that which 

 is required by organs which are called only into action pe- 

 riodically, and in which great activity prevails at certain 

 periods. 



This theory is ingenious, but it has been seen that the 

 main fact upon which it rests is for the most part erroneous, 

 and the basis of the theory being removed, the theory itself 

 must fall. 



In order that it may be seen that the opinions entertained 

 by Mr. Simon, in his Essay on the Thymus, have not been 

 overstated, I will introduce a few passages therefrom : 



" Thus while the completion of cells, within the cavities 

 of the thyroid gland, is assuredly a departure from the habitual 

 state of that organ, and probably the evidence of protracted 

 activity therein ; it is yet just such a direction as may serve 

 even better than uniformity to illustrate the meaning of the 

 structures which present it ; for it shows, beyond dispute, that 

 the dotted corpuscles are homologous with the cytoblasts of 

 true glands." (p. 79.) 



" In the thymus one would at first believe a similar low 



