OR YOLK. 223 



it and the Embryo, and yet is constantly distinct 

 from the former. The Vitdlus is esteemed by 

 Gaertner to compose the bulk of the seed in Futi, 

 Mosses and Ferns, as well as in the genus Zamia, 

 f. 200, closely allied to the latter, see his t. 3, and 

 even in Ruppia, Engl. Bot. t. 1 36, and Cyamus. 

 In the natural order of Grasses the part under con- 

 sideration forms a scale between the Embryo and 

 the Albumen. 



I cannot but think that the Vltdlus is nothing 

 else than a subterraneous Cotyledon. In the Horse 

 Chesnut and Garden Nasturtium, Gaertner almost 

 allows, see his Introduction, p. K51, that they are 

 the same thing. It does not appear that any plant 

 with genuine ascending Cotyledons is likewise fur- 

 nished with this supposed organ ; on the other hand, 

 it is commonly attributed to such as have the most 

 copious Albumen, and therefore should seem to 

 answer some other end than mere nutriment, which 

 is supplied by the latter. The reader may consult 

 Tr. of the Linn. Soc. r. ( J. 204, where this subject 

 is fully discussed. It seems by Decandolle's Fl. 

 Franc, v. 1.157, that Mr. Correa has also exploded 

 the idea of a Vitdlus in plants, but his reasons do 

 not appear. 



We learn from the above inquiries, that the old 

 distinction between plants with'one Cotyledon and 

 those with several may still be relied on, though in 

 the former the part which has commonly been so 



