INTRODUCTION TO BOTANY. xxxvii 



2. the dicotyledons, or those whose embryo has two cotyledons. 

 See Plate 12, and Explanation. We do not find the 

 different parts, which have been mentioned always united in 

 the same plant. There is a certain number of vegetables, 

 which, by the constant deficiency of stamens and pistils, by 

 their external forms, their mode of vegetation and reproduc- 

 tion, differ so much from the other known plants, that they are 

 separated and form a distinct class. Linnaeus gave the name 

 of cryptogamic, that is, plants with concealed, invisible, 

 sexual organs, to distinguish them from the Jlowering, ox pha- 

 nerogamic. The cryptogamic plants, include ferns, mosses, 

 lichens, &c. and constitute nearly the seventh or eighth part of 

 the fifty thousand vegetables, known. As they have no seeds, 

 they have neither embryo, nor cotyledons, and are also called 

 in-emhyyonate or acoiyledonous. Hence the three divisions of 

 vegetables into 1. in-cmhryonate, or acoiyledonous^ including 

 ferns, inosses, &c. 2. erabryonate or phanerogamic, that is, 

 flowering plants; those with evident flowers, seeds, and 

 embryo: these last are distinguished into monocotyledons, or 

 those in which the cotyledonary body of the embryo is of a 

 single piece, and produces a single leaf by germination ; for 

 example, grasses, lilies, &c. (see Plate 12.) and into dicotyle- 

 dons, or those, (with embryo having two cotyledons,) which 

 produce two leaves by germination ; for example, the oak, 

 elm, &c. See Plate, 12. The number of the dicotyledonous 

 plants is greater than that of the monocotyledonous and aco- 

 tyledonous united. 



The Organs of Vegetables 



Are divided into two classes — 1st. Organs of Nutrition or 

 Vegetation ; they serve for absorbing nutritious substances fit 

 for their developement : such are the root, stem, buds, leaves, 

 &c. 2d. Organs of Reproduction or Fructification. 



Organs of Nutrition or Vegetation. 



These are the root, stems, leaves, stipulas, and some of these 



organs in a degenerated state; for ey.^mTp\e, thorns, prickles, 



tendrih. These organs all conduce to the maintenance of 



vegetable life : for example, the root, buried in the ground. 



