ON NATURAL ORDERS. 21 1 



subdivisions indicating the Orders most allied to each 

 other. But in the execution of this plan, difficulties 

 immediately arose, especially respecting the Verti- 

 ciliated 42, whose leaves are invariably opposite, and 

 the Asperifoli(K 41, as regularly furnished with al- 

 ternate leaves. Yet these two Orders could not, in any 

 natural arrangement, be placed asunder. So the Per- 

 sonata 40, chiefly opposite-leaved, were necessarily 

 to be classed near the Luridce 28, and others, with 

 alternate leaves. It is needless to point out exceptions 

 amongst other Orders, or tribes of Genera. 



No discriminating character of his Orders, or 

 " Fragments," was ever formed by Linna3us. On the 

 contrary, he adverts under almost every one of them, 

 in the Pr&lectiones published by Giseke, to the ano- 

 malies or exceptions which militate against such an 

 attempt. His judgment, as I have already hinted, is 

 confirmed by the result of the labours of those who 

 have undertaken this arduous task ; though the world 

 is extremely indebted to them for having, in the face 

 of such obstacles, entered upon it. The difficulties, ap- 

 parent contradictions, and various exceptions, which 

 embarrass them in the detail of their performance, 

 are inherent in the organization of the vegetable body, 

 in which there is throughout no positive or mathema- 

 tical certainty. A few practical observations, illus- 

 trative of this truth, may, not altogether unprofitably, 

 here close the subject. 



Philosophers have attributed to Nature a plastic 



