BIOTYPES AND HYBRIDS. 



17 



050.80: Another original culture which now seems to belong to B. bp. 

 heteris was the offspring of a very robust plant collected in a dooryard near 

 Cold Spring Harbor, Long Island, April, 1906. This plant was taken up 

 and potted in the greenhouse, where its pollination was guarded. The 

 earlier leaves of this plant were recognized as resembling B. bp. heteris, ex- 

 cept in the less sharp attenuation of the primary lobes, but later leaves 

 the climax-leaves were large, and, in addition to the secondary lobes 

 characteristic of B. bp. heteris, they had somewhat quadrangular secondary 



FIG. &.Bursa bur sa-pastoris heteris. Offspring of sib of plant shown in fig. 5. 



lobes in the proximal axils of the primary lobes, and these square lobes 

 were sometimes almost cut off from the primary lobes, giving the leaf the 

 peculiar form usually described as interruptedly pinnate (fig. 7). The 

 seeds of this plant were sown May 23, 1906, and produced 352 offspring. 

 These were badly damaged by the thrips, 81 being killed and 57 so stunted 

 as to make an estimation of their characters uncertain. The remaining 

 214 formed a consistent group unlike its parent and also unlike any other 



