iQoS] SHVLt—MENDELIAN INHERITANCE ill 



From all of these results it must be concluded that the purple disk 

 is a strict Mendelian character, and that the first purple-disked 

 parent was a heterozygote. The original cross is being repeated to 



make 



Lychnis dioica L. 



This plant is a native of Europe and was doubtless very often 

 cultivated in the gardens of a generation or more ago. It has now 

 commonly escaped from the gardens and is maintaining itself quite 

 generally along roadsides in the eastern United States. The flowers 

 show^ considerable variation in the intensity of their purple color, and 

 white-fiowTred ones are quite common. Purple and white flowers 

 have been crossed in so many species and found to follow ^Iexdel's 

 law, that there would have been little incentive to study this particula.r 

 character in Lychnis dioica, had it not been for the fact that this 

 species is dioecious, and that in consequence self-fertilization could 

 not be held responsible for the Mendelian behavior if it should be 

 found to exist. Statements in the mianuals regarding the dioecious 

 habit of this species indicate that it also occurs as a hermaphrodite, 

 but among about five thousand individuals which I have examined 

 only one was noted which had both stamens and pistils, and that one 



le flower w'ith both kinds of sporangia. 

 summer of 1905 I made all possible combinations with 

 white and purple flowers, but in one case unfortunately used two 

 different purple-flowered individuals for the poUination of the same 

 white-flowered plant and collected the seeds from both crosses together. 

 The offspring from these crosses reared in 1906 were as foUows : 



No. 05212, w X w, 90^ 



No. 05213, w X 2 p% 66 p:4i w 

 No. 05114, P X p, 65p:23W 

 No. 05115, P X P, 9<5p 



The 



purpl 



.mg 



ily "purple-flowered young, shows l^etty condu- 

 ^aling here with a Mendelian pair of characters, 

 i faiSly (051x4), which probably represents the 

 ms a considerable departure from the expected 



