THE AGGREGATE ORIGINATION OF PARASITIC 

 PLANTS 



DR. CHARLES A. WHITE 

 Smithsonian Institution 



In the January number of The Naturalist I gave a 

 review of the known phenogamous parasites, in which 

 was discussed the relation of the parasites to one another, 

 and to other abnormal plants ; and the relation of all of 

 them to normal plants. The present- article is devoted 

 mainly to the question of the manner of origination of 

 the parasites as such, which, it is assumed, was by abnor- 

 mal aggregate mutation from normal phenogams. 



Parasitism in the animal kingdom is perpetrated by 

 low, upon higher, forms of life, the parasites belonging 

 to families, orders and even to classes, which are widely 

 different from any of those which include the hosts. 

 Parasitism of low forms of vegetable life upon higher 

 forms is also everywhere prevalent, such as that of fun- 

 goid cryptogams upon phenogams, but the cases now 

 under consideration are those of parasitism of various 

 kinds of phenogamous plants upon other phenogams. 

 Evidence of this phylogenetic relationship of parasites 

 and their hosts, even in extreme cases of parasitic defor- 

 mation, is fortunately preserved in that part of the struc- 

 ture of the parasites which pertains to parturital repro- 

 duction. That is, the florescence and fruitage of the para- 

 sites have remained characteristically phenogamous, each 

 parasitic species having preserved at least those floral 

 and pericarpal structures which normally characterize the 

 phenogamous families, as such. It is thus observable 

 that, in the abnormal mutation which produced the para- 

 sites, the effect was chiefly confined to the somatic parts 

 of the respective plants and to those parts which are con- 

 cerned in blastemal reproduction; while the parts imme- 

 diately concerned in systematic genesis by parturital 

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