142 TISSUES IN GENEEAL. 



additions to the cell-body are formed from the neighboring basis- 

 substance. 



" The basis-substance, under favorable conditions, exhibits in 

 its interior form-changes like those of amoeboid cells. A net- 

 like arrangement, fibrillae, and other forms, come and go. 

 The basis-substance and the migrating cells in it represent a 

 continuous mass, which, according to circumstances, may assume 

 the features of basis-substance or of wandering cells. A lump 

 of this mass becomes a real migrating cell only if separated from 

 its surroundings, which, however, does not occur in the con- 

 tinuity of the substantia propria. 



" The epithelia of the cornea, with their so-called cement- 

 ledges, likewise form a continuous living mass. Under favorable 

 conditions, we can easily realize that neither the cement-ledges 

 nor the cells are stable formations. The cement-ledges are 

 transformed into constituent parts of the neighboring cells, while 

 within the cells new cement-ledges arise, so that after a while the 

 configuration of the epithelium has changed, or else the whole 

 form of the cells of the anterior epithelium is lost to sight, and it 

 appears as a uniform mass, such as is the rule in the normal 

 living cornea. 



" Changes of the branching cells in the substantia propria 

 are easily seen during the first few minutes after excision of the 

 cornea, by suitable methods of preparation. 



" The interior of the cell-bodies undergoes manifold visible 

 variations. One of the most remarkable instances is furnished 

 by the saliva-corpuscles. The assumption that a so-called molec- 

 ular motion takes place in the saliva-corpuscles, is erroneous. 

 The granules seen with insufficient amplifications are transverse 

 sections of trabeculae. The saliva-corpuscle is traversed by a 

 sharply marked trabecular structure (Balkenwerk), which, so 

 long as the corpuscle is fresh, executes lively wavy motions. 

 The waving gradually ceases on the addition of solutions of salts 

 in certain concentration, and the reticular structure disappears. 

 The waving is now replaced by very slow form-changes in the 

 interior mass." 





