424 ANATOMICAL AND PATHOLOGICAL OBSERVATIONS. 



some instances occupying the whole cell. Near the attached 

 extremity of the follicle an irregular passage exists in the 

 midst of the cells, and allows the contents of the cells which 

 bound it to pass on to the branches of the hepatic duct. 



This arrangement of the secreting apparatus may be taken 

 as the type of an order of glands, which consist of follicles 

 more or less elongated. Growth in glands of this kind is 

 regulated by the following laws : 



1st, Each follicle is virtually permanent, but actually in a 

 constant state of development and growth. 



2d t This growth is contemporaneous with the function of 

 the gland, that function being merely a part of the growth, 

 and a consequence of the circumstances under which it occurs. 



3d, Each follicle possesses a germinal spot situated at its 

 blind extremity. 



4Jh, The vital action of some follicles is continuous, the 

 germinal spot in each never ceasing to develope nucleated 

 cells, which take on the action of and become primary 

 secreting cells, as they advance along the follicle. The action 

 of other follicles is periodical. 



5th, The wall, or germinal membrane of the follicle, is 

 also in a state of progressive growth, acquiring additions to 

 its length at its blind extremity, and becoming absorbed at 

 its attached extremity. My brother, in a paper on the 

 ' Development and Metamorphoses of Caligus" read in the 

 Wernerian Society, April 1842, has stated that the Avail of 

 the elongated and convoluted follicle, which constitutes the 

 ovary in that genus, grows from its blind to its free extremity, 

 at the same rate as the eggs advance in development and 

 position. A progressive growth of this kind would account 

 for the steady advance of its attached contents, and would 

 also place the wall of the follicle in the same category with 

 the primary vesicle, germinal membrane, or wall, of the acinus 

 in the vesicular glands. 



