660 THE MICROSCOPE. 



Cells. — All animal and vegetable structures, the micro- 

 scope has revealed to us, are developed from cells or their 

 nuclei ; and the materials for building up animal structures 

 are furnished from tbe yolk and the blood. 



The animal nucleated cell, fig. 300, is more or less of a 

 globular form ; within the delicate cell-wall a granular 

 matter is inclosed suspended in a fluid ; the wall being 

 somewhat darker than the rest. There are usually one or 

 two spherical masses termed nuclei ; these enclose central 

 dots, termed the nucleoli. The size of a cell may be 

 l-300th part of an inch in diameter, some are larger, some 

 smaller; the nucleus may be 1,3000th of an inch in dia- 

 meter ; the nucleolus l-10,000th of an inch in diameter, 

 more or less. 



Of the Cell. — Dr. Beale's views of the cell are so ori- 

 ginal, aud his theory of its development so carefully 

 studied and worked out, that we shall attempt, in as few 

 words as possible, to place them before our readers. The 

 cell has always been considered, and is still so, by many 

 good authorities, to consist, as just stated, of certain defi- 

 nite parts, viz. cell-wall, cell-contents, and nucleus ; to each 

 of which various different functions have been assigned. 

 Many affirm that the vital force is resident in the nucleus 

 alone, while others attribute to the cell- wall, or even to the 

 inter-cellular substance, the power of producing chemical 

 and other changes. Dr. Beale considers this view to be 

 entirely erroneous, and states that every cell or "anatomi- 

 cal elementary part" consists of matter in two different 

 states or stages of existence — matter which lives (germinal 

 matter), and matter which is formed (formed material), 

 and which has ceased to manifest purely vital phenomena ; 

 all living entities, from the smallest living particle to the 

 most complex cell, consist of matter in these two states, 

 the relative proportions of which differ at different periods 

 of the life of the cell, and vary with the different con- 

 ditions under which it may be placed. If a tissue be 

 examined before development has proceeded to any great 

 extent, masses of germinal matter will be found almost 

 continuous with each other, without any appearance of the 

 cells from which all tissues are said to be originally formed. 



