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SEEDLINGS, FOODSTORES AND GERMINATION. 75 



In such seeds as those of the Anemone and Orchids, 

 the original egg cell has only divided a very few- 

 times when the seed falls to the ground for the winter 

 resting period. In the case of Beans, Almonds and 

 Nuts, on the other hand, the embryo has devoured all 

 the starchy or other food material and entirely occupies 

 the seed. 



The embryo of an Anemone or of Wheat may 

 therefore be compared to a squirrel which retires for the 

 winter with a store of nuts, whilst that of the Bean is 

 more like a bear which has grown fat in autumn, and 

 which is contented with the food within itself 



If we examine, under a microscope, sections of 

 ripe seeds we see that they consist of an outer hard 

 coat of protective cells (the testa), surrounding the 

 embryo, and the food of the embryo. The food 

 material varies greatly in different seeds. Generally 

 it consists of two distinct sorts of substances : Proteids, 

 containing nitrogen and sulphur as well as carbon, 

 hydrogen and oxygen, and carbohydrates, composed 

 only of the three last mentioned substances. 



In the wheat grain all four parts are clearly dis- 

 tinguished. The hard protecting skin which covers the 

 seed is made up of the carpels and seed-coat ; the cells 

 are generally very indistinct, having become hardened 

 and confluent. At one end of the grain is the embryo 

 which has a single seed-leaf applied to the food 

 matter behind it, as well as a minute root or roots and 

 a stem bud. Under the microscope the body of the 

 grain is seen to consist of elongated cells with 

 numerous starch grains ; round these latter and next 

 the skin are square-shaped cells which are full of 

 proteids and amides, that is, of those more complex 

 bodies which contain nitrogen {aleurone grains). 



