SEEDS, 



200 



botanists maintain very discordant opinions. Willde 

 now defines the cotyledons to be the entire substance 

 of the seed ; not including the embryo. " Nature" he 

 says " provided plants with their cotyledons, that they 

 might nourish the young plant in its tender infancy. 

 Never yet have I noticed a single instance where this 

 wise measure of nature was omitted. I examined 

 purposely all those plants which were said to want the 

 cotyledons, and always met with them. That in some 

 plants the existence of the cotyledons was altogether 

 denied, and others were said to have one only, others 

 two, and several plants more than two, arose partly 

 from inaccurate observation, partly from mistaking a 

 plant of the embryo for a cotyledon." 



Willdenow obviously includes in his idea of cotyledons 

 the vitellus which most writers regard and describe 

 as distinct. They rarely occur in the same seed, and 

 it is probable that the latter is designed to supply the 

 place of the former, until the first leaf of the young 

 plant is unfolded ; and that the number of cotyledons, 

 though constant in the same, is various in different 

 seeds. 



The Embryo, by Linnaeus deEominated the Corcle 

 is the most essential part of the seed, to which the oth- 

 ers are subservient, and without which it cannot be 

 made to vegetate. It is usually central, being enclosed 

 by the lobes or albumen, as in the umbelliferous plants, 

 or it is excentric as in Coffee, and external as in the 

 Grasses ; it is straight as in the Apple ; curved as in 

 the Kidney Bean, Fig. Ill ; erect as in the Dandelion ; 

 reversed as in Parsnip ; oblique as in Persimmon, Fig. 

 108 ; and horizontal as in the Date Palm. Each embryo 

 is composed of two portions, the rostel or radicle which 



is first evolved during germination, and the phimirfe or 

 * 19 



