WITH THE MICROSCOPE. 317 



As the starch-holding cells increase in size, the starch granules 

 become enlarged by deposition of layer after layer upon their external 

 surface. They still lie embedded in the germinal matter, and are 

 separated from the cell-wall by a portion of it. This part of the 

 germinal matter which lies just within the cell wall was known as the 

 primordial uticle of the vegetable cell. 



The fat cell, or adipose vesicle, is formed in precisely the same way, 

 and fat may be deposited amongst the germinal matter of other cells, 

 such as the cartilage cell, and in nerve and other cells in certain 

 cases. The first formation of fat in a fat cell is represented in 

 pi. LVII, fig. 365. 



ass. Of the Nucleus. In the cell above described, the ' nucleus ' 

 takes no part. What, then, is the ' nucleus,' of which many examples 

 will be seen in the drawings in the plates. The nucleus also consists 

 of germinal matter. It may be regarded as a new centre which has 

 arisen in a pre-existing centre. In many masses of germinal matter 

 there are, in fact, two or three series of centres, one within the other. 

 In one centre (nucleus) there may be one or a vast number of new 

 centres (nucleoli). See pi. LVII I, fig. 347. The nucleus is composed 

 of germinal or living matter, and it has appeared in germinal matter 

 already existing. The vital power or force, whatever its nature 

 may be, always manifests itself in a direction from centres, par- 

 ticles of living matter move invariably in this direction, and as 

 they move further and further away from the centre, their vital power 

 becomes less, but new centres possessing increased vital power make 

 their appearance. These new centres seem to acquire new power 

 while they remain apparently quiescent. The process of acquiring 

 vital power, the development of nuclei with high vital endowments, 

 and the process of taking up a large quantity of pabulum, the rapid 

 increase and multiplication of germinal matter, are opposed to each 

 other. 



384. Of the term Cell. The term ' cell ' was considered to be 

 applicable to all the elementary parts of which organic bodies 

 are composed, notwithstanding great differences which are well 

 known to exist. Not only has it been arbitrarily laid down 

 that a ' cell ' involved the existence of a ' wall,' certain ' contents,' 

 and a ' nucleus,' but distinct properties are still attributed to each of 

 these parts respectively, although no one has ever been able to show 

 that they really performed the offices assigned to them. It is obvious, 

 however, that a small particle of living matter, pi. LVII, fig. 374^ 

 will not fall under the definition given of a cell, nor is it possible, by 

 any reasonable interpretation of the terms employed, to bring white 

 blood corpuscles and a host of other objects into the cell category. 



