236 Retrograde Varieties 



very few indeed, and only rarely, but then often 

 two or three or even more on the same in- 

 dividual. Intermediate stages are not want- 

 ing, but are of no consequence here. The pin- 

 nate leaves obviously constitute a reversion to 

 some prototype, to some ancestor with ordinary 

 papilionaceous leaves. They give proof of the 

 presence of the common character of the fam- 

 ily, concealed here in a latent state. Any 

 other explanation of this curious anomaly 

 would evidently be artificial. On the other 

 hand nothing is really known about the ances- 

 tors of clover, and the whole conception rests 

 only on prevailing views of the systematic rela- 

 tionships in this family. But, as I have already 

 said, further proof must be left for a subse- 

 quent occasion. 



Many instances, noted in our former lectures, 

 could be quoted here. The systematic distri- 

 bution of rayed and rayless species and varie- 

 ties among the daisy-group of the composites 

 affords a long series of examples. Accidental 

 variations in both directions occur. The Can- 

 ada fleabane or Erigeron canadensis, the tansy 

 or Tanacetum vulgare and some others may at 

 times be seen with ray florets, and according 

 to Murr, they may sometimes be wanting in 

 Aster Tripolium, Bellis perennis, some species 

 of Anthemis, Arnica montana and in a number 



