iv] of Glands and Tissues. 113 



gland, that its substance was arranged in small masses essen- 

 tially like those of which a conglomerate gland such as the 

 pancreas was made up; to these he gave the name of acini. 

 Henceforward the mystery which had for so long hung over the 

 liver was cleared away; the liver secreted bile after the same 

 fashion that the parotid and submaxillary glands secreted saliva. 



This is what he says : 



" Since in the higher, more perfect, red-blooded animals, the 

 " simplicity of their structure is wont to be involved by many 

 " obscurities, it is necessary that we should approach the subject 

 " by the observation of the lower, imperfect animals." He ac- 

 cordingly studies in the snail the organ " which by its position 

 "and the connection of its vessels obviously fulfils the nature 

 " and function of a liver." This he finds " to be divided into 

 "a number of lobules, possessing not so much a spherical as 

 "a conical outline. Nor is Nature content to have made use 

 " of such a division merely ; but, in a most liberal manner, has 

 " established a further division into very small parts, visible 

 " only by the aid of the microscope. For each of the lobules 

 "just described is made up of small rounded bodies, like berries 

 " (acini) crowded together after the fashion of a bunch of 

 " grapes, and connected with the whole lobule by means of 

 " vessels." 



He traces out a similar structure in other animals, in fishes, 

 reptiles, mammals, and finally in man, pointing out that these 

 structural features had been dimly seen by others, as by Glisson, 

 who, most accurate observer though he was, was so carried 

 away by his preconceived idea of the continuity of the paren- 

 chyma of the liver, as to refuse to see what was clearly before 

 his eyes. And he thus sums up : 



"In constructing the liver the following seems to be the 

 "constant method of Nature. The vessels in the liver are 

 "distributed in branches carried hither and thither in the 

 "common sheath observed by Glisson, in a manner I say 

 "similar to that which we see in the lung. Around the ends 

 " of each of the vessels, even the slender ones, are attached 

 " lobules maintaining for the most part a conical outline, 

 "not unlike that arising from the division of parts already 

 p. l. 8 



