ANEMONE VIRGINIANA. THIMRLE-WEED. 



95 



European forms, that disquisitions on their real nature have been 

 made by distinguished botanists. In the " Journal of the Proceed- 

 ings of the Linnaean Society, of London," for i860, Mr. Georcre 

 Bentham suggests that the involucre of Anemone was, originally, 

 but a single leaf clasping the stem ; and Professor Asa Gray takes 

 occasion in " Silliman's Journal," of May, in that year, to show 

 from the well-developed involucral leaves oi Anemone Virginiana, 

 here illustrated, what their real nature Is. 



But we may pursue our studies further In the same direction. 

 We may learn from our present species, how closely related all 

 the parts of a plant are, and see very easily how one part is 

 transformed from another part. We must Imagine first that our 

 plant may have had a branching character to a much greater 

 extent than it possesses now. The five petals may have been 

 leaves just as fully developed as the three "Involucral" leaves In 

 our plate but for a greater arresting power of development at 

 that point, in which case the central portion, now stamens and 

 pistils, would have been extended to another flower-stem, and 

 there would have been five axillary buds at the base of each of 

 these five involucral leaves. Just this process has occurred as 

 we can trace in the picture ; except there were but three axillary 

 buds there, and but three leaves. In the arrestadon of the 

 central stem, the three axillary buds were not transformed, but 

 made an attempt to develop Into branches, only again to be 

 arrested by the reproductive force. In this case the whole 

 growth is weakened, and we see was not powerful enough to 

 take more than two nodes into Its rhythmic grasp, making but 

 two involucral leaves, — and these again so weak that no further 

 axial buds could be developed. We gather, therefore, that very 

 slight variations of the rhythmic force connected with the laws 

 of acceleration and retardation make all the differences In struc- 

 ture; and we can understand how very easily one form or 

 species may be evolved from another one. Indeed, we often 

 meet with variations In the normal growdi of our present species 

 which want nothing but permanence to be regarded good 



