POEMATiOX OF DIFFERENT PRODUCTS BY BIOPLASM. 85 



undergo conversion into the formed material or secre- 

 tion of tlie cell, while the entire apparatus hardly 

 changes in volume or alters in form or weight. 



126. Formation of different products by the same 

 Bioplasm. — The above is an interesting example of a 

 mass bioplasm giving rise successively to two different 

 products. It first produces the cell wall, and then 

 gives rise to " products of secretion," the composi- 

 tion and properties of which are entirely different 

 from it. 



I will now refer to one or two other cases in which 

 substances differing in composition and properties 

 from the " cell wall " are formed from the bioplasm 

 within the cell. 



121. Fat Cell. — The fatty matter of the fat cell is 

 formed by the bioplasm after the vesicle or wall of 

 the cell has been produced on its surface. The 

 changes may be studied in the adipose tissue of the 

 white mouse, frog, or other small animal. In the 

 chameleon and many other animals, instead of one 

 globule of oil being formed, and then increasing gra- 

 dually ia size, several minute oil globules result and 

 these accumulate in the cell. Beautiful specimens of 

 fat cells at every stage of development may be obtained 

 from the connective tissue of the frog and newt. 



128. Starch Cells. — Closely resembling the process 

 of formation of fat in the fat cell is the deposition of 

 starch in the starch cells of many vegetable tissues — 

 as, for example, the common potato. If the gradual 

 changes which take place as the bioplasm becomes 

 developed into the mature starch-holding cells be 

 studied, the following observations will be confirmed. 



Little insoluble particles of starch are seen em- 

 bedded iu the bioplasm of the very young cells. 

 These particles increase in size by the deposition of 

 more insoluble starchy matter layer after layer apon 

 their surface, as in the formation of a calculus until 

 the starch-grains assume the perfect form. 



