SECT. I. . THE SEED. 253 



terior integument, which Gaertner has not designated 

 by a proper name, but which I shall call the Sub- 

 testa, lines the exterior integument or Testa, and 

 immediately envelopes the nucleus deriving its 

 origin from the interior portion of the umbilical 

 cord which after perforating the Testa disperses 

 into a multiplicity of ramifications connected by a 

 fine membrane, and forms the interior integument. 

 Like the Testa, to which indeed it adheres, it may 

 be easily distinguished in the garden Bean, or in a 

 ripe Walnut ; in which last it is a fine transparent 

 and net-like membrane, which together with the 

 Testa forms a rind that is generally peeled off be- 

 fore the kernel is eaten, as having rather a hot and 

 bitter taste. To the superficial observer this rind 

 appears, indeed, to consist of only one membrane, 

 but when minutely inspected it is found to consist 

 of two ; which are respectively the Testa and Sub- 

 testa, or the exterior and interior integuments of the 

 seed. The interior integument cannot in all cases 

 be easily distinguished, but Gaertner is of opinion 

 that it is always present, though often rendered in- 

 conspicuous by its adherence to, or incorporation 

 with, the nucleus. 



Like the Testa it consists also of one entire piece, 

 of a soft and pulpy texture till the embryo has 

 reached maturity, at which period it becomes mem- 

 branaceous, and may generally be separated with 

 ease from the nucleus, though not so readily from 

 the Testa. At the point where the ramifications of 



