^r 



GO 



ESSENTIALS OF VEGETABLE PHARMACOGNOSY. 



plants of their respective groups develop 

 a second phytomer lying between the coty- 



Ag.^a. 



Tig 34+ 



P.g. 3a s. 



tig szs: 



F>g.i2i. F,g.. 3a6. T^32^ 



ledons, or if there be but one cotyleJou 

 mostly enwrapped by it. This is the 

 Plumule (Fig. 343 pi.) which shows the 

 same variation in the degree of its devel- 

 opment as that which characterizes the 

 lower. When Its leaves are developed 

 they bear a closer resemblance, as in the 

 figure, to the mature leaves of the plant 

 than do the cotyledons, following out the 

 law referred to in our introduction. The 

 plumule commonly pertains to esalbumin- 

 ous setids among the dicotyledons. 



Terms used to indicate different direc- 

 tions of the radicle refer to its direction 

 with relation to the fruit, its direction in 

 relation to the micropyle being, as has 





F.g 39( 



fig. 335. 



r.g.3ii.. 



r.^.m. F;g.33»* Fig.33b. r-gjafiA. 



g.337. 



been stated, always the same. It is 

 Ascending when it points toward the apex 

 of the fruit. Descending when in the op- 

 posite direction, and Horizontal when 

 intermediate. The latter form is Centrif- 

 ugal when pointing toward the periphery, 



Centripetal when toward the axis. 



The position of the embryo with refer- 

 once to the albumen is always highly char- 

 acteristic. It is Axile or Centric when in 

 the centre of the albumen (Figs. 340 and 

 340A), whether straight or curved; Ec- 

 centric when within the albumen, but out- 

 side of its centre (Fig. 344); Peripheral 

 w^hen lying upon the surface of the albu- 

 men. In the latter position it may be 

 straight or simply (Fig. 345) or circinately 

 (Figs. 34G and 34GA) coiled. The relative 

 sizes of the embryo and the albumen vary 

 from those in which the former is a mere 

 speck in a large mass of the latter to that 

 in which the proportions are reversed, or 

 in which the albumen is entirely wanting. 

 The embryo should in all cases be dis- 



c««- 



T.(, 33? A- 



CO 



t. 



1^3 dhO, 



^ifjyfO J^ f.j.sfs 



sected from the contiguous parts and the 

 relations of its parts to one another made 

 out. It may be straight, variously curved, 

 crumpled (Fig. 347) or variously folded. 

 In the latter condition the radicle may be 

 brought into juxtaposition with the edges 

 of the cotyledons (Accumbent, Fig. 348) 

 or with the face of one of them (Incum- 

 bent, Fig. 349). One cotyledon may en- 

 wrap the other (Fig. 350). When a 

 single cotyledon partly encloses the 

 greater portion of the remainder of the 

 embryo it is sometimes called the Scutel- 

 lum (Pig. 351). Some of the terms appli- 

 cable to the consistency of the albumen 

 are also applicable to that of the coty- 

 ledons. 



