W. F. R. Weldon 239 
seeds were sown, and produced both round and wrinkled seeds, the wrinkled 
(recessive) character becoming " true" only in the fifth year. The wrinkled seeds 
of the second generation from the cross Victoria $ x Telephone </ also gave rise 
to plants with rounded and wrinkled seeds ; but the descendants of these were not 
observed. If Mendel's law of segregation was here followed, his law of dominance 
was not ; because if both are valid, a plant of the second hybrid generation which 
exhibits recessive characters must behave, so far as those characters are concei'ned, 
like a pure-bred individual. The most careful account of seeds of the first hybrid 
generation is that of Tschermak, in the papers already quoted. The variety 
Telephone especially, when crossed with smooth-seeded varieties, gave a large 
number of wrinkled seeds, or seeds of intermediate character. Thus the Pots 
d'Auvergne used by Tschermak had the ripe seeds "always round and smooth"; 
but out of 27 seeds recorded from seven crosses between this pea as the $ and 
Telephone as </ parent, nine were slightly wrinkled, and two out of ten resulting 
from the reciprocal cross were slightly wrinkled. These are difficult cases to 
judge; but the cross Telephone $ x the smooth-seeded Plein le Panier ^ gave 
seeds which " differed only slightly from those of the mother," although the 
wrinkles were perhaps not so deep. Again, Telephone % x the smooth griin- 
bleibende Folger </ gave seeds which certainly belonged to the category 
"wrinkled," although they were more rounded than those of pure Telephone. 
After pointing out the exceptions to dominance of yellow cotyledon-colour already 
mentioned, Tschermak summarises his view of the dominance of wrinkles as 
follows: " Auch in Bezug auf die Form fehlt es nicht an Fallen, in denen sich das 
" sonst dorninirende mit dem sonst recessiven Merkraale in einem gewissen 
" Verhaltnisse combinirte. So ergiebt im Allgemeinen die Bestaubung einer 
"gerunzelteu Markerbse mit Pollen einer glattsamigen Varietat abgerundete, 
" schwach gerunzelte Produkte, und zwar eher als die umgekehrte Verbindung 
"der Eltern." 
This is a sufficient statement of Tschermak's result, so far as it concerns races 
of P. sativum. Correns (No. 3) found that the griine spate Erfurter Folger- 
Erhse which has round smooth seeds, was not dominant in this respect over the 
Pahl-Erhse mit purpuri-othen Hiilsen. 
The foregoing crosses show that the law of dominance does not always hold for 
the shape of seeds, when the races crossed belong to the species P. sativum. The 
race of P. arvense called Graue Riesen is held by some botanists to belong to a 
different " species," and may therefore be considered separately. Tschermak has 
crossed Graue Riesen with five races of P. sativum, and he finds that the form 
of the first hybrid seeds follows the female parent, so that if races of P. sativum 
with round smooth seeds be crossed with Graue Riesen (which has flattened, 
feebly wrinkled seeds), the hybrids will be round and smooth or flattened and 
wrinkled, as the P. sativum or the Graue Riesen is used as female parent. There 
is here a more complex phenomenon than at first sight appears ; because if the 
flowers of the first hybrid generation are self-fertilised, the resulting seeds of the 
