58 THE FRUIT. 



o-\Tile. In this case the ovule, or seed, is said to be orthotropous (erect), Ex. can- 

 dleben-y (Myrica). More generally, however, the funiculus (91) extends beyond 

 the hilum, passing under the integuments partly ai'ound the nucleus, before it 

 is joined to it. The point of this final juncture is always the chalaza, and that 

 part of the funiculus which then inteiwenes between the hilum and the chalaza is 

 called the raphe. This form of the ovule, or seed, is called anatropous (inverted), 

 and is exemplified in the apple. The raphe can, therefore, exist only in the ana- 

 tropous seed, and seiwes to distinguish it. (See Fig. 11 ; No's 8 and 9.) 



122. The Albumen. ( Next witliia the integuments, there is a 

 white substance called the albumen, consisting cliiefly of starch!^ 

 It constitutes the j'chief bulk of some seeds, as maize, wheat, 

 rye, and sei-ves to nourish the embryo in its nascent state.) It 

 abounds chiefly in those seeds which have but one cotyledon. 

 It is wholesome and nutritious, even in poisonous plants. The 

 albumen in some seeds is entirely wanting/' particularly in the 

 bean,tpea, &c., the nutritious matter being all absorbed in the 

 cotyledon. 



123. The EMBRYO is an organized body, the aaidiments of the 

 young plant, situated within the integuments. To the growth 

 of tliis all other parts of the seed are subsei-vient. In some 

 seeds the embryo is distinctly visible. Ex. bean, Convolvulus. 



124. The embryo is divided into tlnree parts ; the radicle, the 

 plumule, and cotyledon. 



a. {The i-adicle'is the descending part of the embiyo, destined 

 to form the root (radix). Li respect to position, it always points 

 towards the foramen. 



b. The PLUMULE is the ascending part of the embiyo,\ or the 

 rudiment of the ascending axis of the future plant. It is usually 

 directed towards the chalaza. 



125. The COTYLEDON is the bulky, porous, and faiinaceous 

 part of seeds, destined to form the fii-st or seminal leaves of the 

 young plant, as well as to afford nourishment to the plumule 

 and radicle, before they can obtain it from the earthy In the 

 bean, squash, cucumber, and most other plants, the cotyledons 

 are conspicuous ui rismg above the gi'ound. 



a. The number of cotyledons is variable ; and upon this cir- 

 cumstance is founded f the most important and distinct division 

 of the Ph.(Enogamia, or flowering plants.' 



126. Monocotyledonous plants are those whose seeds have but one cotyledon. 



