518 GENCHO FUJIMURA 



while the secretions are mostly fluid, it follows that it would be no 

 great error to take it that, viewed simply from the histological 

 standpoint, the so-called secretion, after all, means, the liquefac- 

 tion of secretory granules. However, the modes of liquefaction are, 

 according to my view, so varied that they should by no means 

 be dealt with in one and the same manner, but rather there are, 

 roughly speaking, several forms, such as are given below, 

 according to the kinds of glandular cells, or according as the 

 cause which prompts secretion differs. 



First form. This is observed in certain mucous cells. The 

 secretion is brought into being simply by the melting down and 

 growth of secretory granules which have developed in a fixed 

 degree, and, different from many other glandular cells in which 

 the secretory granules are mostly preproducts of secretion, 

 the granules here in this case show the same reaction as secre- 

 tion (that is, mucin) from the beginning of their appearance 

 and find themselves already identical with the secretion as early 

 as they appear. This fact was demonstrated by M. Heiden- 

 hain in the goblet cells of the intestine of the salamander, and 

 it is, in general, difficult to tell definitely the time of liquefac- 

 tion in what is covered by this form. 



Second form. This is observed in many mucous cells. The 

 granules, while in the first stage, appear as a certain preproduct 

 (mucigen), and undergo a chemical change simultaneously 

 as they have developed to a certain degree, and are changed 

 into the ordinary secretion (i.e., mucin). Mention has been 

 made to this effect by Biedermann (the mucous cells of the 

 frog) ; M. Heidenhain and Nicoglu, '93 and '98 (the skin glands 

 of a salamander) ; Altmann, '94 (the submaxillary glands of a 

 cat); Maximow, '01 (Glandula retrolingualis of a hedgehog). 



TMrd form. This is often seen in ordinary serous cells. As 

 the functions begin, the secretory granules begin to hquefy 

 gradually on the periphery and, although it appears that the 

 granules are imbedded for a certain period in the secretion al- 

 ready formed, they finally change thoroughly into secretion, and 

 then appear as simple vacuoles within the cell bodies. The 

 clear halos around the granules referred to by Langley ('34), 



