SECT. I. THE SEED. 263 



seed that is itself acotyledonous may yet in ger- 

 mination produce a plant that shall be furnished 

 with a cotyledon, which seems to be the case with 

 the Mosses. It should also be further observed 

 that there are cases in which a seed having 

 naturally but two lobes may by accident acquire a 

 greater number. I have more than once opened a 

 Hazel-nut whose kernel or cotyledon consisted of 

 three lobes instead of two, its usual number. The 

 lobes were nearly of an equal size, each consisting of 

 about a third part of the kernel, and approaching to 

 the shape of a triangular prism. The kernel was 

 externally of the usual shape, and perfectly soimxi 

 and good. 



There is yet an additional distinction that has 

 been instituted among cotyledons, and that may be 

 here taken notice of. It is that by which they are 

 divided into Epigaan and Hypogaan cotyledons. 

 The Epig&an cotyledons are such as spring up 

 during the process of germination above the surface of 

 the earth, and are converted into what are usually 

 called seminal leaves ; being sometimes thick and 

 fleshy lobes, as in the case of leguminous plants, and 

 sometimes thin and foliaceous as in the case of the 

 Carrot and Radish, though generally different both in 

 shape and structure .from the future leaves of the 

 plant. The Hypogaan cotyledons which are pecu- 

 liar perhaps to dicotyledonous seeds, are such as do 

 not discharge any conspicuous function during the 

 process of germination, or undergo any perceptible 



