MUCUS-CORPUSCLE. 207 



generally termed mucus. This mucus, which is being con- 

 stantly removed in small quantities as it is formed, is said 

 to be secreted by the mucous membrane. It is, however, 

 formed upon the surface in glandular follicles by small par- 

 ticles of bioplasm. In fact, by careful microscopical ex- 

 amination, the apparently homogeneous viscid matter is 

 found to contain multitudes of oval or spherical bodies, or 

 corpuscles, which are transparent and granular. From the 

 changes in form which these continually undergo, it is cer- 

 tain that the matter of which they are composed is almost 

 diffluent. The so-called mucus corpuscles consist of free 

 particles of bioplasm which have no cell-wall. They are 

 separated from one another by, and are embedded in, the 

 more or less transparent, viscid, tenacious substance formed 

 by them and termed mucus. (PL III, fig. i.) 



No language could convey a correct idea of the changes 

 which may be seen to take place in the form of one of these 

 minute particles of bioplasm, while alive. Every part of the 

 substance of a particle exhibits distinct alterations in out- 

 line within a few seconds. The material which was in one 

 part of it may move to another part. Not only does the 

 position of the component particles alter with respect to 

 one another, but change in position is constant. There is 

 not, however, a mere alternation of movements like that 

 occurring in the contraction and relaxation of a portion of 

 muscular tissue. Were it possible to take hundreds of 

 photographs at the briefest intervals, no two would be 

 exactly alike, nor would different gradations of the same 

 change be exhibited j nor is it possible to represent the 

 movements with any degree of accuracy by drawings, 

 because the outline is changing in many parts at the same 



