PROTOPLASM. 



covering, envelope, or cell-wall results. In this way the 

 life of the germinal matter is preserved until the return of 

 favourable conditions, when the living matter emerges from 

 its prison, grows, and soon gives rise to a colony of new 

 amoebae, which exhibit the characteristic movements. 



Mucus Corpuscle. Every one knows that upon the 

 surface of the mucous membrane of the air-passages, even 

 in health, there is a small quantity of a soft viscid matter 

 generally termed mucus. This mucus, said to be secreted by 

 the mucous membrane, contains certain oval or spherical 

 bodies or corpuscles, which are transparent and granular. 

 From the changes of form which take place in them, it is 

 certain that the matter of which they are composed is 

 almost diffluent. These corpuscles or cells are mucous cor- 

 puscles, but they have no cell-wall. They are separated 

 from each other by, and are embedded in, a more or less 

 transparent, viscid, tenacious substance formed by the cor- 

 puscles, and termed mucus. (Plate II, fig. i.) 



No language could convey a correct idea of the changes 

 which may be seen to take place in the form of the living 

 mucus or pus corpuscle ; every part of the substance of a 

 corpuscle exhibits distinct alterations within a few seconds. 

 The material which was in one part may move to another 

 part. Not only does the position of the component particles 

 alter with respect to one another, but it never remains the 

 same. There is no alternation of movements. Were it 

 possible to take hundreds of photographs at the briefest 

 intervals, no two would be exactly alike, nor would they 

 exhibit different gradations of the same change ; nor is it 

 possible to represent the movements with any degree of 



