ANALOGIES AND AFFINITIES. 49 



plants, if not quite tlie same, is very near to it ; so near that 

 tlie one suggests the other yery distinctly ; and Lindley 

 (Nat. Syst. 140) quotes De CandoUe as having remarked that 

 the caterpiUar of the Cabbage butterfly feeds exclusively upon 

 CrucifertB and Tropaolum. This must be a case of pure 

 analogy ; not an index of relationship. The morphological 

 gap betAveen them is much too Avide. But it ought here to be 

 remarked that the real affinities of Tropcvohim are with an 

 assemblage of plants noted for their mimicry in the matter of 

 odors and flavors. From the genus Pelargonium one might 

 indicate a long series of species each one of which so imitates 

 the odor of some other herb or fruit that a blindfold botanist 

 familiar with them could identify such species of the genus 



by their odors alone. 



The Capparidete are always and everywhere looked upon 

 as next of kin to the Craciferae ; and I am entirely of the 

 opinion expressed by Lindley that these are the only plants 

 to which the Cruciferre have any aflinity whatsoever ; that 

 the anthological and carpological resemblances which such 

 genera as Chclldonium and Glaucium bear to cruciferous 

 types^resemblances which the Jussieus and De Candolles, 

 Adanson, Spach, Baillon, Bentham and many more have 

 construed as denoting a real affinity-are analogies only ; 

 merely casual surface mimicries from which nothing of real 

 consanguinity can satisfactorily be inferred. " Ihe totalJ> 

 different structure of the seed" is Lindley's apparently con- 

 clusive argument against the consociation of Papaveraccffi 

 with Crucifer«.. Additional support, but of le.ss strength, is 

 given to Lindley's view in my mind, in the fact that the juices 

 in the former are always lacteous and narcotic, whereas among 

 the latter in no instance is there revealed a trace of such 



^ls\he herbage of the capparids is more generany glandii- 

 lar-pubescent and oily to the touch than that -^ t'-J-^; 



fers so the odor which they e^^--^^^/^ "^^^^P" Stu"' 

 intense ; but it is a different kind of odor, -f -ithst^l ng 

 that th; adjective vocabulary in this realm of knowledge is 



MISSOURI 

 BOTANICAL^ 



GARDEN. 



