Parallel Mutations. 49 



segregation is apparently the same type of behaviour as was found 1 

 in the P 3 and F 3 of crosses between the large-flowered CE.rubricalyx 

 and the small-flowered (E. biennis, in which large and small flowers 

 frequently appeared on the same plant, and even long and short 

 petals, of varying lengths, on the same flower. It is possible that 

 this race of (E. lamarckiana var. cruciata, which emanated from 

 the Bremen Botanic Garden, may have originated by a cross 

 between CE. biennis leptomeres and (E. lamarckiana. This hypo- 

 thesis is supported by the short style in the flowers of this race, so 

 short that, like (E. biennis, nearly all the flowers were self-pollinated. 

 But in crosses between (E.biennis and its cruciate mutation there are 

 no reports of this vegetative segregation, with both types of flowers 

 on the same plant. 



As a result especially of the studies of MacDougal (1905) and 

 Bartlett (1914a), a number of cruciate species and varieties are 

 now accurately known. As Bartlett points out, it is clear that 

 these have not had a common origin, but they have arisen 

 independently from different stocks, some more remotely and some 

 more recently, just as var. leptomeres apparently originates even 

 now from (E biennis L. The first cruciate form to be discovered 

 was CE. cruciata Nutt. Its taxonomic history is given by Bartlett. 

 Nuttall found it in Massachusetts and sent seeds of it to several 

 botanists. Don grew it in 1824 and described it under NuttalPs 

 name. The species which is still cultivated in botanical gardens 

 under this name is quite likely descended from this original source. 

 Its variable petals indicate that it has been crossed with a broad- 

 petalled species, and it is now called CE. cruciata, var. varia, de 

 Vries. 2 In the sixth edition of Gray's Manual (1889) it was classed 

 as probably a rare garden sport, since no specimens had been 

 collected except in gardens, subsequent to the original collection 

 over 60 years earlier. In later years cruciate specimens were 

 collected in Vermont. 



The interest awakened in wild North American CEnotheras 

 by the work of de Vries, soon led to the discovery of other forms. 

 Seeds of a cruciate form which had been collected at Sandy Hill, 

 New York, near Lake George, in 1902, were divided, part of them 

 being grown by MacDougal (1905) at New York, and a larger 

 number by de Vries at Amsterdam. This material contained two 



1 See Gates, 1917a. 



* De Vries found that this variety segregated roughly into three groups, 

 (1) cruciate, (2) intermediate, (3) broad-petalled. The latter is constant except 

 for rare cruciate bud mutations. 



D 



