58 



ESSENTIALS OF VEGETABLE PHARMACOGNOSY. 



persist, and usually does, upon the matur- 

 ity of the seed. It is known as the Endo- 

 sperm. As the embryo develops it stores 

 within its own body more or less nutri- 

 ment At maturity we may find that the 

 entire store of nutriment has thus been 

 transferred to the body of the embryo, 

 and the seed is said to be Exalbuminous, 

 or we may find more or less endosperm or 

 perisporm, or both, when the seed is said 

 to be Albuminous, and this nourishment 

 is known as the Albumen. In only a few 

 seeds used in medicine does the albumen 

 consist in any part of perisperm. The 

 chemical nature of the albumen is ex- 

 tremely variable. l*rotection to the em- 

 bryo may be aftorded by the albumen 

 when that is of the required consistency 

 or composition, the conditions of the latter 

 being a mere parallel of those already 

 considered under the subject of the peri- 

 carp. More frequently, however, it is se- 

 cured entirely through the coats of the 

 seed. These may correspond to the coats 

 of the ovule, though usually the primine 

 is found to have disappeared. When it 

 persists it takes the name of Tegmen, or 

 Endopleura, the secundine becoming the 

 Testa, or Exopleura. Rarely the secun- 

 dine also disappears and the seed is 

 Naked. The seed will also be naked when 

 produced from a naked ovule. When one 

 or both of the coats persists, the point 

 where the foramen existed becomes the 

 Micropyle. Frequently the development 

 of a new coat external to the others is 

 induced by fertilization, and this is 

 known by the general name of Aril. If 

 it develops from the chalaza or a lower 

 point it is called an Arillus, or True Aril ; 

 if from the micropyle, an Ariilode, or 

 False Aril. 



their study by the pharmacognosist, and 

 this is especially true of the histology 

 of all their parts. Inasmuch, however, as 



r 



the subject of histology has been referred 

 to a separate portion of the work, we 

 shall here consider only such characters 

 as can be distinguis-hed by means of an 

 ordinary lens. 



The hilum is in most cases readily per- 

 ceptible, but is occasionally found only 

 by minute examination. It is to be studied 

 as to its position, size, form, surface and 

 color. Its position is sometimes fixed 

 with reference to the form of the seed, as 

 at the larger or smaller end, upon the 

 broad side or on the edge, as well as with 

 reference to the micropyle, adjoining it, 

 at the opposite end or at some intermedi- 

 ate point. It is the last mentioned char- 

 acter which determines the class of seed 

 as to its tropism. In size the hilum may 

 be a slight i>oint or covering a consider- 

 able portion of the surface. Its form is 

 frequently characteristic as heart-shaped 

 (Fig. 314) or linear and channeled as in 

 Fig. 315. Its color frequently differs 



markedly from that of the remainder of 

 the seed. 



The rhaphe, extending from the hilum 

 to the chalaza when these do not coincide, 

 is ordinarily not perceptible upon the 

 surface. When it is so, as in Figs. 316 

 and 316A, its appearance is of great diag- 

 nostic value and must be closely scru- 

 tinized. The chalaza in its simple form 

 calls for no especial attention. If, how- 

 ever, an enlargement appears at this 

 point (the Strophiole, Fig. 317), it must 

 not be overlooked. The strophiole may 

 develop into the arillus (Fig. 317A), a 

 partial or complete covering, and its 

 characters call for the same attention 



The provisions of the seed for securing which is requisite for the testa, 

 dissemination are in most respects com- 

 parable with those affecting the pericarp. 

 Wind distribution is pre-eminent; that by 

 fixation to passing bodies is frequent, and 

 that by means of an edible coat is rare. 



The fixation of seeds disseminated with 

 out the pericarp is favored by their small 

 size, enabling them readily to enter crev- 

 ices and cavities, and by peculiarities of 

 surface which favor the same process. 



The large number and importance of 



The testa is not wanting in any medic- 

 inal seeds. In general it is not closely 

 adherent to the underlying tissue, and it 

 can be readily removed. In Its thickness, 

 consistency, surface, color and appen- 

 dages it yields important pharmacognos- 

 tical characters. It may be pitted (Fig. 

 318), tuberculate (Fig. 319), reticulate 

 (Fig. 320) or hairy (Fig. 316), and the 

 minute characters of its pits, tubercles, 

 ridges or hairs must not be overlooked. 



medicinal seeds lend great importance to It may be dull or shiny, and its color may 



