ON THE GERMINATION OF SEEDS. 77 



In flowering plants reproduction takes place by means of the 

 germ or embyro contained in seeds, and in the tubers and bulbs 

 of the root. In the seed, the germ developes into radicle or root, 

 and plumule and stem, between which is an axis connecting the 

 two, and communicating with the cotyledons or seed lobes, which 

 contain the food destined to nourish the young plant till able to 

 extract nourishment from the ground for itself. A deposition of 

 this food is likewise laid up in the cells of the bulb or tuber, and 

 to it the general name of albumen, from its fancied resemblance 

 in functions to the white of an egg, has been given. It is ge- 

 nerally enclosed in a hard or bony case, for protection from in- 

 jury, (but which it is not necessary to the growth of the germ,) and 

 consists of mucilage or gum, sugar, and fecula or starch, which 

 are all convertible substances, consisting of different proportions 

 of carbon, hydrogen, and oxygen, which by chemical analysis, 

 have been found to stand as under, viz. 



By the continued deposition of carbon, very ripe seeds and tu- 

 bers contain more starch or dour than unripe seeds : and from 

 the difficulty of reducing starch again into mucilage, which must 

 take place in the vegetating process, befors it can be rendered a 

 soluble food for the young embyro, ripe seeds will be found to 

 keep longest, and to survive accidents of bad treatment better 

 than unripe seeds ; which, however, from having their food in a 

 state more easily rendered soluble, are found both in seeds and 

 tubers to spring more quickly, and if sufficiently far advanced, 

 with more vigour than ripe seeds or tubers. In the process of 

 germination, when carried on in the usual manner, if a seed is 

 picked up, the cotyledons will be found filled with a soft mucila- 

 ginous substance, generally of a milky colour and sweetish taste. 

 This is the food of the young embryo reduced into a soluble 

 state, and is conveyed through the vessels of the cotyledon to 

 the axis, and thence to the radicle and stem. On the quantity of 

 this food furnished depends the vigour with which the young 

 plant will shoot ; and hence the best means of reducing the albu- 

 men of the seed or tuber into a soluble food in the speediest 

 manner, and in the greatest quantity, is the greatest desideratum 



