GENERAL ANATOMY OF THE GLANDULAR SYSTEM. 79 



small acini. Some other glands, as the Prostate, appear to be 

 uniform in their texture, and have none of this granulated 

 appearance. 



The structure of glands has long been an interesting object 

 of anatomical inquiry, and was investigated with great assiduity 

 by those eminent anatomists, Malpighi and Ruysch. 



Malpighi, as was formerly observed, used ink and other 

 colored fluids in his injections. He was also very skilful in 

 the use of microscopes, and took great pains in macerating and 

 preparing the subjects of his inquiries. Ruysch, on the other 

 hand, used a ceraceous injection, and was most eminently suc- 

 cessful in filling very small vessels with it. Malpighi believed 

 that there were follicles or cavities in glandular bodies, which 

 existed between the extremities of the arteries and the com- 

 mencement of the excretory ducts of those bodies, and that in 

 these cavities the secreted fluids underwent a change. — Ruysch 

 contended, that the arteries of glands were continued into excre- 

 tory ducts, without the intervention of any cavity or follicle ; 

 that the small bodies which had been supposed to contain folli- 

 cles or cryptae, were formed by convolutions of vessels, and that 

 the change of the fluid, or the process of secretion, is produced 

 by the minute ramifications of the artery. 



A very interesting account of this subject is contained in two 

 celebrated letters, which passed between Boerhaave and Ruysch 

 in the year 1721, and are published at the end of the fourth 

 volume of the works of Ruysch. 



The opinion of Ruysch has been more generally adopted by 

 anatomists, and has derived support and confirmation from 

 several anatomists since his time. The late Mr. Hewson 

 declared his conviction that the small globular bodies which 

 are scattered through the kidneys, and were supposed to be 

 follicles or cryptae, are merely convoluted arteries. He also 

 asserted, that the acini which appeared in the mammae as 

 large as the heads of pins, when the excretory ducts of that 

 gland were injected with vermillion and painter's size, proved 

 to be the minute ramifications of the excretory duct, which 



