184« VEGETABLE ORGANOGRAPHY. 



The seed properly so called, such as I have defined it, 

 must be distinguished from monospermous fruits and 

 tubercules ; thus, it may be confounded, as it frequently 

 has been in botanical, and as it constantly is in ordinary 

 language, either with a monospermous pericarp adherent 

 to the seed, as the caiwopsis, such as the seed of the 

 Wheat, or with the body which proceeds from the 

 union of a solitary seed with the pericarp and calyx, as 

 the achenium of the Compositse ; or with this same 

 achenium also united with the involucellum, as in Sco- 

 lymus. In all these cases the seed forms part of the 

 body to which it gives its name, but it is not isolated, 

 and unless one take care to separate it, either really or 

 in imagination, from the organs to which it is joined, it 

 will be impossible to understand its description. 



On the other hand, one is often inclined to take for 

 seeds, the tubercules or bulbs which are produced in 

 certain parts of plants, but which are germs developed 

 without fecundation. The distinction of the seeds from 

 these bodies is often very difficult, sometimes impossi- 

 ble ; therefore, to avoid all uncertainty, I shall derive 

 all that I have to say from the seed of plants in which 

 this doubt does not exist, and I shall leave for the 

 following chapters the examination of the doubtful 

 cases. 



A seed may be considered as a germ which is de- 

 veloped in the axil of a leaf, curved upon itself in the 

 form of a closed envelope. This fecundated germ takes 

 the name of Embryo ; the leaf which surrounds it, that 

 ofSpERMODERM ( sjoermodermis J , or skin of the seed: 

 these are the only two organs essential to the ripe seed. 

 We sometimes find in the spermoderm another body, 

 which is called Albumen, and which deserves special 

 attention ; the spermoderm, albumen, and embryo, will 

 be, then, the three parts which we shall have to study. 



