STRUCTURE AKD FORMS OF THE SEED 



99 



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be uniform or variegated (Fig. 321). Its 

 lustre or shade of color is frequently of 

 the greatest assistance in determining 

 the age, freshness, mode of preparing or 

 preserving or other conditions on which 

 the comparative medicinal quality of the 

 seed depends. The enlargement at the 

 micropyle (the Caruncle, Fig. 321A) calls 

 for the same scrutiny as the strophiole. 

 It may be variously appendaged (Fig. 

 323), and like the latter it may extend 

 into a partial or complete covering, the 

 arillode. The arillus, or arillode, may be 



discernible upon section of the latter as 

 slender veins, giving us the so-called 

 Ruminated Albumen (Fig. 338). 



The albumen is characterized chiefly 

 by its consistency, being bony, as in the 

 ivory nut and date; horny, as in nux 

 vomica; oily, as in the castor oil and 

 cacao; fleshy, mealy, etc. In sectioning 



the seed note should be taken of the 

 presence, number, position and forms of 

 any cavities which may exist in them. 



The embryo calls for the most thorough 

 and minute study as a basis for system- 



partial, as in Fig. 322, or complete, as in atic work, though for the pharmacogno- 



the seed of the Euonymus. 



Appendages to the seed do not always 

 take the form of an aril of either class, 

 nor is their origin confined to the points 

 from which the aril develops. Either as 

 aril or appendage from the general sur- 

 face it exhibits a great variety of form, of 

 equal importance with those which char- 

 acterize the pericarp. Forms of especially 

 frequent occurrence are exhibited by Figs, 

 324 to 329, Important distinctions some- 

 times exist between seeds bearing similar 

 appendages, as regards the points from 

 which the latter originate, as in the case 

 of strophanthus, false and true. 



The general form of the testa is, of 

 course, that of the seed, and calls for 

 terms applicable to the forms of solid 

 bodies (Figs. 330 to 337). 



The tegmen when present is extremely 

 thin and tightly adherent to the nucellus, 

 following closely all inequalities upon the 

 surface of the latter, and occasionally 

 having its intruded folds caught between 

 the forming masses of the albumen and 



sist only the more important details of its 

 general structure need be considered. It 

 has already been stated that it consists of 

 one or more phytomers. The part first 

 formed is the internode, which becomes 

 the Caulicle (Figs. 339 to 340A, ca.), in 

 old works denominated the "Radicle." 

 The Radicle (in the last named figures) 

 is the extreme tip of the caulicle, which 

 points always in the direction of the 

 micropyle. From this point the root is to 

 be developed. The embryo may consist of 

 nothing further than the caulicle, and 

 even this may be of the most elementary 

 character. Ordinarily, however, there de- 

 velops at the node (the point opposite to 

 the radicle) one or more Cotyledons, or 

 Seed-leaves (cot, in the figures). Most 

 seeds which possess but a single cotyledon 

 (Fig. 341) are grouped together in a di- 

 vision of the Angiosperms, which for this 

 reason are called Monocotyledons, those 

 with two in the Dicotyledons. A few 

 plants, mostly Gymnosperms, are poly* 

 cotyledonous (Fig. 342). The highest 



