BOTANY, *3 



PHYSIOLOGY OF PLANTS. 



Phytology, or the physiology of vegetables, may pro- 

 perly* be divided into : 1st. The germination and growth 

 of plants from the seed ; 2d. The propagation of plants ; 

 3d. The increase of plants, or the enlargement of their 

 volume. 



1. THE GERMINATION AND GROWTH OF PLANTS FROM 

 THE SEED. 



If a seed be immersed in warm water for a considera- 

 ble time, and then subjected to a high magnifying power, 

 the elementary form of the future plant may be seen. In 

 some seeds even the embryo of the future flower becomes 

 manifest. Therefore it may not be absurd to say, that 

 the germination and growth is effected by the develope- 

 mnt of the embryo plant contained in the seed. And 

 that this developement goes on by means of successive sup- 

 plies of nutriment, whichris taken into an organized 

 structure adapted to its reception. 



But where shall we stop in our views of these elemen- 

 tary forms ? Shall we say, that within the embryo of the 

 future flower which sometimes becomes manifest under 

 the microscope, there is probably another seed containing 

 the elementary form of the next generation, and so on ad 

 'infinitum ? 



Fortunately the present state of the science presents 

 the means of fixing the limit in the most satisfactory 

 manner. For nothing in the physiology of organized be- 

 ings is better established, than that a perfect future seed 

 cannot be produced without the application of pollen from 

 a stamen, to the nistil of a stigma. But if the future 

 seed were perfect in the present one, such an operation 

 would not be necessary. Therefore by the aid of the mi- 

 croscope and this established law, we are enabled to in- 

 fer, that a seed may contain the elements of a future plant 

 as Car as the flower and empty tegument of the future seed, 

 and no farther. 



. THE PROPA CATION OF PLANTS. 

 There are two methods of propagating plants. First* 

 by reproduction; second, by continuation. 



1. A plant is reproduced, when it grows immediately 

 from the seed. 1 he potatoe is reproduced; when the 



G 2 



