264 BOARD OF AGRICULTURE. 



The nucleus comprises the embryo, or germ, and its store 

 of food for the early days of germination. In the seeds of 

 many plants this store of food is incorporated Avith the germ ; 

 for instance, pease, beans, and squashes have the food in the 

 substance of the embryo, forming one body with it. In corn, 

 wheat, and the other cereals, the germ occupies a small space 

 at the lower part and at one side ; while on the other sides of 

 the germ, and above it, the food makes up the bulk of the 

 grain. The germ of a seed is a rudimentary plant having a 

 leaf or leaves, and stem, which are extremely reduced in 

 size, and frequently much disguised in shape. The amoimt 

 and character of the food within the seed, and the stage of 

 development of the germ, depend, of course, upon the degree 

 of maturity. 



Under the microscope a seed is seen to be made up of cells 

 or minute compartments, which are arranged in an orderly 

 manner, and which have various contents. The most impor- 

 tant of these to be now mentioned are starch and proteine 

 matters. The starch exists as minute grains, having general 

 resemblances of shape in seeds of the same kind. The shapes 

 and some other characters are so nearly constant that they en- 

 able an expert to identify the kinds of starch from different 

 sources. Frequently associated in small amount with starch, 

 but often replacing it altogether, there are solid fats or oils, 

 concerning which nothing further need now be said. The 

 proteine, or nitrogenous, substance in seeds, constitutes the 

 material out of which the living matter in the plantlet, the 

 protoplasm, is to be constructed. Considered, therefore, mi- 

 croscopically, a seed is a structure made up of closed com- 

 partments, some of which contain materials like starch, to be 

 used in building, and proteme matters, which are to become 

 protoplasm. 



Without dwelling upon the chemical composition of seeds, 

 attention may be called to the fact that a seed represents in 

 its constitution a certain amount of treasured force, or 

 " energy of position." It represents in its oxidizable sub- 

 stances a definite work performed by the plant on which it 

 ripened: this may be likened to a weight which has been, 

 by the expenditure of force, elevated to a given height, and 

 which, by virtue of its position, is capable, when released, of 

 performing in its descent a certain amount of work; or it 



