246 GENETICS IN RELATION TO AGRICULTURE 
TaBLe XXXIX.—Resutts or Various Marinas or rubrinervis (R.) AND nanella (N.) 
AND THE Forms Propucep From SucH Marttnes (compiled from 
de Vries, “Gruppenweise Artbildung’’) 
Parentage Sree Lamarckiana|Rubrinervis Subrobusta tig ‘norms 
Per cent. Per cent. | Per cent. | Per cent. 
Nanella X rubrinervis........... 105 73 ee 27 
Nanella X rubrinervis........... 79 59 at 41 
Rubrinervis X nanella........... 70 59 ae 41 
(N. X R.) subrobusta............| 160 as 10) | 80 ae 10 
(R. X N.) subrobusta............ 160 Ae 3 85 ye 12 
(R. X N.) subrobusta............ 56 ne 34 52 o. 14 
(N. X RB.) subrobusta............| 230 oe 21 70 eh 9 
(R. X N.) subrobusta............| 2384 i 15 73 a 12 
Lamarckiana * R. nanella.......| 152 3 a 77 20 
R. nanella * lamarckiana........| 152 25 xe 32 43 
(N. xX R.) lamarckiana X nanella| 266 86 a ae 14 
(N. X R.) lamarckiana X nanella 70 80 ae a 20 
(R. X N.) lamarckiana X nanella| 112 76 ae ao 24 
Nanella X (R. X N.) lamarckiana 68 62 x aa 38 
Nanella * (N. X R.) lamarckiana 27 55 28 be 45 
(R. xX WN.) lamarckiana X R. | 
EIT ecto oe sys mena Se eaaien | 34 | 3 Tel abe ile 2h 
Nanella K (N. X R.) subrobusta. . 45 | 33 16 ae | 51 
R. nanella K (R. X N.) subrobusta| 204 | of 33 se 67 
(N. X R.) subrobusta X nanella...| 138 | 51 | 20 i 29 
(N. X R.) subrobusta X R. nanella| 246 ee 75 aa 25 
(N. X R.) subrobusta * R. nanella| 214 72 ee 28 
(R. X N.) subrobusta X R. nanella| 289 72 a 28 
parent that the phenomena exhibited, although complex, are very orderly; 
but no very consistent Mendelian interpretation has been advanced to 
account for all of them. 
The hypothesis of de Vries while ingenious does violence to many of 
our most cherished conceptions of the general nature of hereditary 
phenomena. De Vries assumes that pangens exist in three forms; 
active, labile, and inactive. Two pangens are concerned in the above 
series of forms, the rubrinervts pangen for strengthening of the vascular 
bundles and the nanella pangen for stature. These pangens exist in 
lamarckiana in the labile condition in which they occasionally change 
to the inactive condition and thus produce the corresponding muta- 
tions rubrinervis and nanella. Labile pangen X inactive pangen then 
gives according to de Vries in Ff; the ascendency of either one or the 
other condition to the complete exclusion of the other form in later 
generations. Accordingly lamarckiana X nanella gives in Fy lamarck- 
tana and nanella which breed true in further generations. Similarly 
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