SECRETORY FUNCTIONS IN HUMAN PLACENTA 521 



is at last dissolved altogether and is changed into secretion, 

 while at the same time the Kapuze is also condensed, and forms 

 itself into secondary granules, later on to be drained out along 

 with the secretion, thus bringing about an entirely granule free 

 condition of the cells. This form of secretion was first detected 

 and examined closely by M, Heidenhain in the pelvic gland of 

 a salamander and in the lacrimal gland. Subsequently, Nicolas 

 ('92), in a man's lacrimal gland. Held ('99), in a rabbit's sub- 

 maxillary gland, and Fleischer ('04), in a cow's lacrimal gland, 

 observed and proved the appearance of the crescent-shaped small 

 bodies described above. 



The above does not cover all the forms of granular liquefi- 

 cation at the time of glandular secretion, and yet it will be 

 quite clear how varied the modes of liquefi cation are. 



Now, I will discuss a little further the origin, and therefore 

 the manner in which supply is made of secretory granules, 

 this problem being the second in importance with respect to 

 glandular secretion. 



With regard to the origin of secretory granules, the problem 

 itself is a very difficult one indeed, but it should be noted that, 

 along with the sudden increase of studies on plastosomes in re- 

 cent years, many authors have attempted a solution of this 

 troublesome question. 



Below I give a general account of the result of these researches. 

 Generally speaking, every author equally agrees in the argument 

 that every glandular cell always has within the cell body plasto- 

 somes as constant ingredients and, though the quantity and 

 arrangement of the latter are certainly varied, it is the usual condi- 

 tion that while the serous cells are in a state of rest the numerous 

 plastosomes are chiefly arranged in rows along the long axis of 

 the cells. These plastosomes, however, generally decrease in 

 quantity considerably during the period of secretion, especially 

 when the cells are filled, and they are then found largely, close 

 to the basement membrane of the cell, while near the lumen, 

 they are either entirely absent or, if they are found, they are 

 between the granules in a very small number. And in mucous 

 cells, in contrast to serous cells, the plastosomes are found largely 



