CELL FORMATION. 665 



passing from the embryonic to the adult state, the outer 

 part of the germinal matter undergoes conversion into 

 formed material, which increases as the supply of pabulum 

 becomes reduced. 



Dr. Beale, in short, considers that " all formed matter 

 results from changes in the germinal matter, and that the 

 action of the cell really consists in a change from the living 

 to the lifeless state of the matter of which it is composed ; 

 and that the products formed by the cell do not depend 

 upon any metabolic action exerted by the cell-wall or 

 nucleus upon the pabulum, nor are they simply separated 

 from, or deposited by, the blood." And he looks upon 

 the "living cell" as a minute body, consisting partly of 

 living matter influenced by vital force, and partly of life- 

 less matter resulting from the death of the first, in which 

 chemical and physical changes occur, which may be 

 modified by the influence of surrounding substances and 

 external forces. 



In pursuing the subject of cell development, we shall 

 proceed by the aid of our old lights in this intricate path 

 of physiological science. And it is only right that we 

 should add, that the views we have endeavoured to place 

 fairly before our readers have not been unhesitatingly 

 accepted, but, on the contrary, those of the German school 

 are greatly preferred by many physiologists. 



Change of Cells into Tissues. — This may take place by 

 a joining together or coalescence of cells in a rudimentary 

 state. Cells may meet, and at the point of contact coalesce 

 and run into each other, thus forming a tube ; indeed, 

 in this manner minute tubular structures are formed. 

 Another mode is : cells aggregate into a mass, and at the 

 point of contact run into each other, thus producing a 

 multilocular cavity ; Ko. 9, fig. 300. Glandular struc- 

 tures are formed in this way. Membrane is formed of a 

 deposit from the cytoblastema ; before the cell-membrane 

 is formed, the substance from the cytoblastema coalesces 

 with those particles close at hand, thus forming a delicate 

 film-like membrane. This membrane Professor T. Wharton 

 Jones calls endosmotic, retentive membrane. We have 

 the cells coalescing to form a filament or fibre. The nucleus 

 may disappear, or form another structure ; and where 



