122 STARCH ITS ORIGIN. [BOOK i. 



are derived. So long as a hilum or point of attachment is 

 admitted to exist, so long the starch grains may be supposed 

 to grow from the sides of the cells. That view is adopted by 

 Payen ; but we sometimes find crowds of starch grains in 

 cells, filling the entire cavity, in which case the central grains 

 cannot have any communication with the cell walls. This 

 occurs in Maize, and is fatal to the theory of starch grains 

 springing from cell walls. 



The late Mr. Quekett has given the following description of 

 the manner in which he believed that he had seen the starch 

 grains form. (See Annals of Natural History , vol. xviii. p. 193.) 



" In the very young stem of Circsea Lutetiana, or the young 

 branch of the Grape-Vine, the different appearances presented 

 by the grains of starch, from their perfect state down to their 

 first commencement, may be readily observed by making 

 numerous sections from the lowermost internode up to the 

 terminal joint. The cells most recently formed are so filled 

 with mucilage and granules as to be opaque ; lower down the 

 granules begin to disappear, and the cytoblast is apparent ; 

 still lower, the cytoblast appears to have lost its granular 

 character without having much increased in size, and has 

 become a minute cell, with a distinct nucleus, instead of a 

 congeries of granules with a larger central one. On the 

 outside of this nucleated cell, granules (varying in number 

 from ten to twenty) make their appearance, at first very 

 minute and of a green hue, and afterwards enlarging and 

 becoming colourless ; and as they increase in size the 

 nucleated cell is absorbed, and the granules become free. 

 At a later period a multiplication of the granules takes place 

 by fission and pullulation, certain grains exhibiting marks of 

 subdivision, and others having minute granules attached to 

 them ; and generally more grains of starch are found in a 

 cell than the number of minute granules seen developing on 

 the nucleus. Several of these stages are more readily seen 

 in the tuber of the Potato. If a slice be removed from its 

 exterior, so thin as only to pass beneath the cuticle, and a 

 very thin and perfectly transparent slice be then taken and 

 examined under the microscope, the cells in the central 

 portion are seen to contain only a few grains of starch, 



