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 the prevailing views of the systematic 

 relationships in this family. But, as I have al- 

 ready said, further proof must be left for a sub- 

 sequent 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 



