356 



The journal ot Heredity 



the case of the fran- 

 ciscana cross is doubt- 

 less related to the fact 

 that the latter species 

 has thicker, stiff er 

 leaves than Oe. La- 

 marckiana, and that 

 the stiffness of the 

 lea\es is to a certain 

 degree antagonistic to 

 the revoluteness pro- 

 duced by the funifolia 

 factor. In all cases, 

 howe\'er, the funifolia 

 character has been 

 sufficiently well devel- 

 oped, that an error of 

 classification has oc- 

 curred only in one or 

 two cases. 



In the adult stage 

 the chief difference 

 between mut. funifol- 

 ia and its parent, Oe. 

 Lamarckiana, aside 

 from the revolute 

 lea\es of the former, 

 consists in the lack of 

 basal branches in 

 funifolia, such as are 

 invariably present in 

 La ma rckiana . The 

 characteristic habits 

 of these two forms are 

 well shown in Figures 

 14 (right) and 15. 



SUDDEN' APPEARANCE 

 OF SEVERAL MUTANTS 



OR "mass mutation" 



The first funifolia 

 jilanls appeared in 

 1918 in pedigree fam- 

 ily numi)er 17 20, the 

 offspring of a self-fer- 

 tilized Lamarckiana of 

 to their narrower shape, the leaves of ftiuifolia are grayish on the the cross-bred stram 

 \'entral surface, a characteristic which is not found in the parent, mentioned above. 

 Photograph by James I'. Kelly. (Fig. 9.) IMiere were five indi- 



margins are limited to the basal portion vidualsof {he funifolia type in a family 



FUNIFOLIA COMPARED WITH ITS PARENT 

 On the left are two leaves (one showing the ventral surface, the 

 other showing the dorsal) of thv fuuifolia mutant; on the right are 

 two of the f)arcnt, Oc. Lainarckiiuiu, arranged in the same manner. 

 Here i> Wrought out in striking manner the ditTerence in leaf-form 

 which has entitled the mutant to the name funifolia. In addition 



of the leaf-blade. Thisunder-develop- 

 ment of the funifolia characters has 

 belli particularly noticeable in the 

 case oi funifolia segregates from crosses 

 with Oe. framiscana. This result in 



consist mg of 100 individuals, 90 of 

 which were typical Oe. Lamarckiana. 

 When these five plants were first ob- 

 served in pot culture in the greenhouse 

 they had the appearance shown in 



