552 THE AMERICAN NATURALIST [Vol. L 



Thus we have evidence that in a third species (for as 

 such there seems good ground for regarding this wild 

 type) doubles appear in F 1 when a cross is made witli a 

 double form. The behavior in this respect of the other 

 new form has not yet been ascertained. 

 . With regard to P. nyctaginifora the seed of which was 

 collected from Punta Ballena, Maldonaldo (Uruguay), it 

 was noticed that the plants were not entirely uniform in 

 color, some showing a very definite tinge of purple on 

 the outer side of the flower tube, others scarcely a trace. 

 Similar variations had also been observed in the original 

 (1906) commercial material. Whether this variability is 

 normal to the species or is an indication of crossing is 

 not certain. It is somewhat remarkable that in this 

 original material all the 8 individuals tested proved to be 

 self fertile and yielded abundance of seed, whilst six 

 self-pollinated flowers on three of the Uruguay plants 

 taken at random did not yield a single seed. It seems un- 

 likely that this result could be due to accident, or to a 

 difference of conditions due to the fact that the 1906 

 plants were grown in the open, whereas the individuals 

 grown from the wild seed were kept in pots in a cool 

 house. Indoor treatment had not been found to affect the 

 fertility of the other strains, and it is hardly likely that it 

 did so here; but this point is now being verified. Only 

 one Uruguay plant was crossed with pollen from a double 

 (Ventura 2). From this cross the same result was ob- 



