66 



THE BEGINNINGS OF LIFE 



of silica and phosphates^ always enters into the com- 

 position of the latter. In the calculi there is much 

 mineral matter and a smaller quantity of colloidal ma- 

 terial • whilst in starch-grains there is a large proportion 



a 



m 



ji* 



...»■: « V 



Fig. 42. 



Different kinds of Starch-granules contrasted with Globular Carbonate 



of Lime. (Rainey.) 





Ordinary forms of potatoe-starch. 



h, b\ Compound granules of ' tons les mois' starch. 



c. 



Two carbonate of lime ' calculi' coalescing, from the calcifying 

 shell of an oyster. 



of colloidal material and a small proportion of mineral 



matter. 



The mode of appearance and the character of the 

 starch-grains which are to be found in the cellular tissue^ 

 are best studied by making thin sections of any grow- 

 ing plants in which starch is usually formed in large 

 quantities. Very young potatoe-tubers answer well for 



t 



this purpose. When sul 

 nation. Mr. Rainev savs 



1 



•*^In such sections, in this 



and the majority of plants, the starch-cells in 



r 



^ See ' Jrnl. Microsc. Science/ i860, p. 2. 



the 



0^ 





p 



be either free ^ 



ned togethei 



mewliat tr 



d joi 



tell or so 



fouEd with shreds ( 

 vested more or les 

 ire remote the gi 

 tkir increase in si 

 ■ber, showing n 



t of the UE 



. the number 



some of the starch -I 

 ''«J all could bec^ 



tthe 



mate i 



space 



increase 

 in which t^ 



'"? ^bout the < 



