610 



THE AMERICAN NATURALIST [Vol. XLIX 



The true H. animus appears to be quite unknown in 

 the wild state, but nevertheless the monocephalic char- 

 acter may have arisen among wild plants. Dr. Church 

 makes the following suggestion: 



If the monocephalic form is the giant of cultivation derived from the 

 Prairie form, it should be possible to repeat the history, by growing 

 Prairie forms in quantity, and selecting the suitable mutations when they 



idea has been that, knowing what to look for, it might be possible to get 

 somewhere near it in say 10 years; though the Indians possibly took 



cephalic strain is the response to selection for close cultivation (about 

 two plants per square yard). The solitary heads are required for simul- 



2. H. lenticularis Douglas. The prairie sunflower, 

 much branched, and normally with dark disc. It has 

 been regarded as the wild type of H. annuus, but Ryd- 

 berg treats it as a distinct species. In crosses with 

 typical annuus, the F 1 is intermediate, often with a 

 tendency to fasciation. If annuus and lenticularis are 

 considered specifically distinct, we have to face the diffi- 

 culty that the former is known only in cultivation, and its 

 one " specific " character, the monocephalous habit, is 

 not constant. 1 The color of the disc is not a reliable 

 distinction, since yellow discs occur in wild plants. 

 Possibly the variation shown by H. annuus may be ex- 

 plained by contamination with lenticularis, since some 

 strains, at least, are constant in their characters. At 

 present, however, it seems probable that no wild species 

 ever existed with typical H. annuus characters ; the actual 

 facts would probably be best represented by considering 

 lenticularis the species, and annuus a cultivated variety 

 derived therefrom. Since, however, the latter was first 

 named, the species-aggregate will have to be called H. 

 annuus, and the nomenclatural outcome will be as fol- 



