40 



ON STEMS. 



Caroline. I thought that endogenous plants were 

 those which grew in our own country, in opposition to 

 exotics, or plants of foreign countries ; but, by your ac- 

 count, it is just the reverse, for endogenous plants grow 

 in countries most distant from us. 



Mrs. B. You confound the word endogenous with in- 

 digenous: the latter signifies to grow within the country; 

 the former is a French word, not yet introduced into the 

 English language, signifying to grow internally, or with- 

 in itself. 



Caroline. Within itself ! How can the stem increase 

 in size internally ? One would think that the new layers 

 of wood growing in the interior part of the stem would 

 burst the external coats. 



Mrs. B. The more the external coats are pressed 

 by the new growing wood, the closer and more compact 

 they become, and the greater the resistance they offer 

 to the internal layers ; till at length a period arrives when 

 the outer coats are so hardened and distended as to yield 

 no longer : the stem has then attained its full growth in 

 horizontal dimensions, and offers a broad flat circular 

 surface to view, which has scarcely risen in height above 

 the level of the ground. 



Emily. How singular a mode of growing ! In this 

 first stage it must resemble the stump of the trunk of a 

 tree which has been cut down ; but how does it grow up 

 afterwards ? 



Mrs. B. The following spring, there being no room 

 for a new layer of wood to extend itself horizontally, it 

 shoots up from the centre of the stem vertically ; fresh 

 layers every year successively perforate this central shoot, 

 till from the innermost, it becomes the outermost layer 

 of wood ; hard, compact, and of the same horizontal di- 

 mensions as the base : the second period of growth is 

 then completed ; and thus the stem continues growing, 

 for a certain number of years, horizontally, and then takes 

 a sudden start upwards. 



176. What did Caroline suppose endogenous plants to bel 177. 

 With what word did she confound the term endogenous! 178. What 

 is the signification of indigenous 1 * 179. What question does Caro- 

 line ask in relation to the meaning of the word endogenous'? 180. 

 How does Mrs. B. describe the internal growth of the stem'? 181. 

 How does she describe its growth after there is room for a new layer of 

 wood to extend isself horizontally 1 



