362 



The Juurnal ot Heredity 



OENOTHERA LAMARCKIANA 



Sinn- the work of Professor Hugo Dc Vries with niulants 

 of Oe. Lamartkiiitui, this phitit has been extensively used by 

 students of genetics. In the accompanying i)aper, Professor 

 Shull describes three new mutants which have originated at 

 Princeton, and whicli are likelv to |jro\ e \ er\- useful. (I'ig. 

 15.) 



This beautiful mutation hasappeand 

 in t^vo pc-cli^rtr families (Nos. 2047 and 

 2052) whith were progenies of two 

 sihs in family No. 108 of m>' cross- 

 bred strain of ()v. iMnuinkiana, in 

 1020, and this fad makes it certain 

 that the gene-mutation which made the 



realization of the velanrea color 

 possible occurred at least as 

 early as 1919. Steps have been 

 taken to test the extent to 

 uhich the recessive vetaiirea 

 factor, I', is distributed in the 

 cross-bred strain of Oe. La- 

 niankiana and the results of 

 these tests should indicate 

 Aviiether the vetaiirea gene- 

 nmtation probably occurred 

 previously to 1919 or not. 



Family 2052, in which vet- 

 aurea was first discovered, 

 was the progeny of a typical 

 specimen of Oe. Lamar ckiana, 

 and the single vetaurea speci- 

 men in this family was in all 

 respects, except the color of 

 the flowers, a typical pink- 

 coned Lamarckiana. The 

 other members of this family 

 were all rubricalyx, being the 

 I'l of a cross between La- 

 niarckiana and the character- 

 istic homozygous alethal 

 segregate from Oenothera ru- 

 bricalyx, which I call Oe. lati- 

 frons. Only an accident of 

 technique w^hich resulted in a 

 self-fertilization of the mother 

 plant made it possible for the 

 vetaiirea specimen to appear 

 in this family. 



The parent of 2047, the 

 other family in which mut. 

 velanrea has appeared, was 

 itself a mutation in the cross- 

 bred Lamarckiana family 198. 

 It differed from Lamarckiana 

 in having the bud-cones nearly 

 free from red pigment, and 

 the stems a clearer green, Imt 

 fineK' speckled with red pa- 

 pillae as in Lamarckiana. The 

 capsules were a little less well 

 de\ eloped and slightly moredi- 

 \ergent than in Lamarckiana. 

 One of the two zygote lethals character- 

 istic of Lamarckiana was also wanting 

 in this green-budded mutant as shown 

 by the fact that family 2047, produced 

 1)>- self-fertilization, split into (a) the 

 parinl ty pi". nameK, green-budded near- 

 Lanuirckiana, and (b) uvAV-dcci/fiens, 



