224 TESTA, THE SKlK. 



denominated is the Albumen^ as in Corn, the real 

 Cotyledon of \vhich is the scale or Vilellus, which 

 last organ however seems wanting in Palms, Lilies, 

 &c.. such having really no Cotyledon at all, nor 

 any thing that can perform its office, except the 

 stalk of their Embryo, which indeed may answer 

 the purpose of a Cotyledon, just as the stems of 

 many plants fulfil the office of leaves. In the Horse 

 Chesnut, Oak and Walnut possibly, whose seed- 

 lobes do not ascend, the functions of a real Coty- 

 ledon, as far as air is concerned, and those of the 

 Albumen mav be united in these lobes, as is the 

 case with most Leguminous plants ; which is ren- 

 dered more probable, as several of the latter have 

 the corresponding parts likewise remaining under 

 ground. Hence the divided " VitdluSy' as Gsertner 

 terms it, of the Cyamus is to be considered as a pair 

 of subterraneous Cotyledons, and the plant conse- 

 quently ranges near its natural allies the Poppy tribe, 

 as Mr. Salisbury, without the aid of physiology, has 

 shown in the Annals of Botany, x\ 2./?. 70, 75. 



Testa^ f. 4, the Skin, contains all the parts of a 

 seed above described, giving them their due shape ; 

 for the skin is perfectly formed, while they are but 

 a homogeneous liquid. This coat diftersin thickness 

 and texture in different plants. It is sometimes 

 single, but more frequently lined with a finer and 

 . very delicate film, called by Gaertner Membrana^ 



