78 



LETTER V. 



a lion agree in a very great number of their principal 

 points of organization ; and are therefore in affinity 

 also. But a cat and a bird, although both of the 

 animal kingdom, disagree in the greater part of their 

 structure ; they therefore are not in affinity with each 

 other. 



To take an illustration from plants you are now 

 familiar with, compare the Crowfoots with the 

 Myrtles ; they both bear flowers composed of calyx, 

 corolla, numerous stamens and pistils, and they both 

 have leaves with netted veins and consequently an 

 exogenous structure ; but here their resemblance 

 ceases. — Compared as to other circumstances they 

 are extremely different : as you will see by studying 

 the two following columns : — 



Crowfoots have 



Lobed leaves, with an acrid wateiy 

 juice, and usually with an altei'- 

 nate insertion on the stem. 



Numerous stamens, arising from 



below the carpels. 

 A superior pistil, consisting of 



several carpels, either not at all 



or but shghtly adhering to each 



other. 

 As many styles as carpels. 



A very httle embryo, which is 

 furnished with a great quantity 

 of albumen for its nourishment 

 when young. 



They are chiefly herbs. 



Myrtles have 



Leaves not at all lobed, usually 

 with an opposite insertion on 

 the stem, and Avith a volatile 

 oily juice, which is lodged in 

 little transparent spots. 



Numerous stamens arising fi'om 

 the sides of the calyx. 



An inferior pistil, consisting of 

 several carpels, which are all 

 growii into one solid body at 

 the top of the fruit-stalli. 



Only one style, whatever the num- 

 ber of carpels. 



An embryo, which is supplied 

 with no albumen for its nou- 

 rishment when young. 



They are all trees or shrubs. 



