JUSSIEU'S 

 NATURAL SYSTEM. 



1. The grand character upon which the Jussieuan 

 system is established, is derived from a consideration 

 of the cotyledons or seed-lobes. 



On examining the seeds of plants, they will be found to differ in 

 tliis point of their anatomical structure ; some will be found to have 

 no lobes, as with the genus eqnisetum or horse-tail ; others with 

 one lobe ; and some with two lobes or more. 



2. Upon the structure of the seed, therefore, Jussieu 

 first arranges all vegetable productions into threegeneral 

 divisions; for which he has proposed the terms ofacoty- 

 ledones, monocotyledones, and dicotyledones. 



Acotyledones when the seed-lobes are not present or indistinct ; 

 monocotyledones when there is one lobe ; and dicotyledones when 

 there are two or more lobes. 



3. These three general divisions are further subdi- 

 vided into fifteen classes, the characters of which are 

 derived, first, from the number of cotyledons ; next 



