374 CHANGES SUCCEEDING IMPREGNATION. CHAP. VIII. 



Position The figure of the seed is often also altered in pass- 



oftheseed. f . i 



ing from its young to its mature state; changing 



from smooth to angular, from tapering to oval, from 

 oval to round, and from round to kidney-shaped. 

 But all seeds are not brought to maturity of which 

 the rudiments may exist in the ovary. Lagcecia 

 and Hasselquestia produce uniformly the rudiments 

 of two seeds, of which they mature but one.* 



But the principal changes resulting from im- 

 pregnation are operated in the seed itself, which, 

 though previously a homogeneous and gelatinous 

 mass, is now converted into an organized body, com* 

 posed of different membranes enveloping,, or en- 

 veloped by, one another, 



The testa. The Testa, which is the external coat of the seed, 

 is formed from the original cuticle of the nucleus, 

 and augmented by means of the juices conveyed to 

 it through the umbilical cord. Hence it is some- 

 times formed, but never capable of being detached 

 from the mass of the nucleus, previous to fecunda- 

 tion ; after which it is easily, though not spontane- 

 ously separated, till the maturity of the fruit. 



Subtesta. The Subtestci, which is the inner coat of the seed 

 and lies immediately under the testa, originates in 

 the interior vessels of the umbilical cord, which are 

 prolonged in a multiplicity of ramifications through- 

 out the whole membrane, is soft and pulpy till the 

 embryo is matured; as the juices by which the embryo 

 is nourished pass through it. It is seldom distin- 



* Gaert, De Seminibus. 



