LETTER XI. 



107 



as it does to an identity in nature and character, — in 

 structure and function. For he puts the bud on a 

 level with the seed, calling them both embryos,'' — 

 and he indicates the differences that obtain between 

 them by calhng the one a fixed embryo, the other a 

 free embryo ; — differences, these, which attach, not to 

 the essence of the two objects, but to the ends to be 

 accomplished by them in the economy of nature, — 

 and which, therefore, important as they are in that 

 respect, may, in a physiological point of view, truly 

 be regarded as incidental, 



6. It is unnecessary to dwell longer on these views 

 of M. Du Petit-Thouars. But familiar as I have been 

 these many years with the whole passage in Richard 

 which we have just been considering, there is an 

 expression in it which has only now for the first time 

 occurred to me as peculiar. The seed is spoken of as 

 containing an embryo ; and the bud is said to be 

 analogous — not to the entire seed, but only to the 

 embryo within it. There is a real propriety in this 

 distinction. Besides the embryo, there is enclosed 

 within the seed a quantity of starch for the earliest 

 growth of the embryo. The bud contains none. But 

 observe, the pith in the shoot to which the bud is 

 attached consists of starch, and holds precisely the 

 same relation to the bud, as an embryo, that the 

 starch of the seed does to its proper embryo. The 

 analogy, instead of being weakened by this distinction, 



