10 THE MENDEL JOURNAL 



An important consideration whicli this dis- 

 covery of parthenogenesis in Nicotiana opens to 

 discussion, is the supposed hybrid nature of N. 

 Sanderw. This plant is said to be a hybrid of N. 

 Forgetiana x N . affinis. The former species was 

 brought by one of j\Ir. Sander's travellers from South 

 America, and it is said was then crossed with N . 

 affinis. But the true history of this hybrid appears 

 to be shrouded in mystery. 



In the light of these observations on partheno- 

 genesis in Nicotiana, it is conceivable that Sander may 

 have obtained amongst the Fi offspring from his cross of 

 N . Forgetiana x N. affinis not only some true hybrids 

 which he possibly destroyed, but'also some individuals 

 derived from the parthenogenetic seed of N . Forgetiana. 

 He may have selected these and sent out the seed as 

 the type of the supposed hybrid N. Sandercr, In other 

 words, N . Sander <v may simply be N. Forgetiana. 

 If this is so, it will explain what is, from the Mendelian 

 standpoint, the remarkable fact that the supposed 

 hybrid N. Sander ir breeds true to seed, for this is a 

 phenomenon which is not expected to occur, on Men- 

 delian principles of gametic purity and segregation. 



Parthenogenesis in Nicotiana perhaps explains a 

 fact which I have frequently observed, namely, when 

 Nic. Sanderw is growing alongside of other varieties 

 of Nicotiana in the open it always seeds true. This 

 remark applies equally well to other Nicotiana which 

 I have grown. 



