72 Germination of Seeds. 



equivocal generation, or a common matter of vegetation, which 

 issues into various forms, according to accidental circumstances. 

 It is, however, more consonant to observation, and to the method 

 and wisdom displayed by the Creator in those parts of his works 

 more tangible to our senses (especially when we take into con- 

 sideration the millions of millions of sporules contained in a 

 single fungus, as the common pufiTball, or the many hundreds in 

 the common blue fungus of the cheese), to suppose that they are 

 reproduced by myriads of microscopic pores floating in the at- 

 mosphere, dispersed by currents of air, and only called into 

 existence when the accidental circumstances of moisture, putre- 

 faction, &:c., necessary to their developement, are present. 



In flowering plants, reproduction takes place by means of the 

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

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

 and plumule or 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 injury 

 (but which is not necessary to the growth of the germ), and con- 

 sists 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. : — 



Carbon. Oxygen. Hydrogen. 



Gum to consist of - - 42-23 SO-Si ' 6-93 



Sugar - - - - 42-27 50-63 6*90 



Starch - - - - 43-55 49-68 6-77 



By the continued deposition of carbon, very ripe seeds and 

 tubers contain more starch or flour than unripe seeds ; and, from 

 the difficulty of reducing starcii again into mucilage, which must 

 take place in the vegetating process before it can be rendered a 

 soluble food for the young embryo, 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 yoimg embryo reduced into a soluble 



