90 APHYLLON UNIFLORUM. ONE-FLOWERED BROOM-RAPE. 



or EpipJicgus Virgmiaiia, which seems to confine itself especially 

 to that tree. But this one is a sort of general lover. While in 

 the North attaching itself seemingly to the roots of any decid- 

 uous tree, in the South it is reported as growing in pine woods ; 

 and the inference is that the roots of the pine afford it suste- 

 nance in such cases. De Candolle, in his " Prodromus," notes 

 that it has been found on composite herbaceous plants, espe- 

 cially on the Golden Rod, or Solidago ; and it is probable that it 

 has no choice, but will attach itself to anything that comes first. 

 This fact is of itself a particularly interesting one, for it has been 

 suggested that those parasites which have green leaves, like the 

 mistletoe for instance, feed only on the crude sap, which by the 

 aid of their green leaves they elaborate to suit the special wants 

 of their own organisms. On the other hand, the colorless para- 

 sites are supposed to feed on the sap already elaborated by the 

 parent plant, not having any green leaves of their own, through 

 which, as the student knows, the food of plants is usually pre- 

 pared. If this be so, our ApJiyllon, feeding on so many varied 

 kinds of plants, should present varied chemical combinations. It 

 is hardly probable that any great difference will be found, but 

 the suggestion may serve to show in what direction original 

 discoveries may yet be made. Again, we know that in scaly bul- 

 bous plants, as in the lily, the scales are imperfecdy developed 

 leaves ; and that as the plant grows, perfect leaf-blades appear. 

 We may therefore from analogy look on the scales of our 

 present plant as being imperfectly developed leaves ; and yet no 

 one has ever known leaves to be perfectly produced. It is not 

 probable that these scales are of any more use to the plant in its 

 present condition than though the stem was perfectly round, and 

 all trace of scales absent; and it is such facts as these which are 

 often employed in aid of the doctrine of evolution. It would be 

 contended that this plant was not always leafless as now, — that 

 at some time in the long past it had perfect leaves, but assuming 

 a parasidc character, and finding itself in a condition to do with- 

 out leaves, failed to produce them perfectly any longer. This view 



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