SECTION IV 



SEEDS 



The seed is the body produced from the ovule as the result of fertili- 

 sation. It consists ordinarily of two seed-coats, an outer or testa 

 and an inner or tegmen, enclosing a kernel composed of the embryo 

 with one or more cotyledons and in many cases an endosperm. Some- 

 times an outgrowth (arillus) is developed from the funicle or from the 

 placenta which may extend so as partially or even almost entirely to 

 enclose the seed. 



Most seeds may be readily distinguished from one another on account 

 of the great diversity in their size, shape, surface, structure, and 

 contents. Those with which the student will have to deal may be 

 very minute (black mustard, lobelia, henbane) or of considerable size 

 (calabar bean, cola seed) ; they may be spherical, ovoid, reniform, 

 &c. ; the surface may exhibit a great variety in the sculpture of the 

 outer wall, which may be pitted (mustard seed) or variously reticulate 

 (poppy, henbane, lobelia), &c. Further, the epidermal cells may be 

 prolonged into hairs (nux vomica, strophanthus), or contain mucilage 

 (linseed, mustard seed), or offer other distinctive characters. 



The internal structure of the seed-coats also possesses valuable 

 diagnostic features, but these are only visible under the microscope. 

 A section examined with a lens often exhibits the disposition of the 

 cotyledons and radicle, and allows of the presence or absence of an 

 endosperm being determined ; the endosperm itself varies considerably 

 in its nature, being oily, mucilaginous, horny, ruminate, &c. 



In examining small seeds the student should constantly employ 

 a hand lens with the aid of which the surface should be carefully 

 observed. Transverse sections cut with the aid of a sharp penknife 

 or razor should also be scrutinised. Large, hard seeds such as 

 nux vomica should be soaked in hot water till they are sufficiently 

 softened to be cut. 



STAVESACRE SEEDS 



(Semina Staphisagriae) 



Source, &c. Stavesacre, Delphinium Staphisagria, Linne (N.O. 

 Ranunculacecs), a stout erect herb attaining 4 feet in height, is 



