SPECIES CROSSES LN THE GENUS NICOTIANA. 207 



Plants of the two parent species grown under identical 

 conditions flowered, N. paniciilata on July 13 and N. langs- 

 dorfii a few days earlier. 



The great majority of Nicotiana hybrids produce flowers 

 some days earlier than the mean flowering period of the 

 parents. 



The hybrids were ver}' small and stunted. The flowers 

 were perliaj)s somewhat nearer to N. paniculata in shape and 

 colour ; the habit so stunted as compared with either parent 

 that it was diffloult to ascertain the relative indebtedness of 

 the h^^brid in this respect. The oval, nearly sessile, leaves 

 were puckered at the base, as if in an attempt to become 

 stalked and cordate. 



Fruits were produced with a few apparently perfect seeds, 

 but none of the latter germinated. 



1.— PARTLY FERTILE HYBRIDS. 

 Nicotiana rustica x paniculata. (Plates 22 and 23.) 



This hybrid and its offspring have been described in great 

 detail by Kolreuter and other excellent observers. For this 

 reason, and also because only a small number of plants was 

 obtained in F 2, and these of uncertain parentage, it will be 

 unnecessary to give a minute description of the first generation 

 of hybrids. 



The intermediate character of the h;ybrid may be recognized 

 from an inspection of Plates 22 , 23, and 27. In most respects 

 their aspect appears to be decidedly nearer that of N. rustica 

 than that of N. paniculata. The accompanying tables 

 contain details with regard to the size and proportions of the 

 flowers. 



The 22 hybrid plants of F 1 grown in the open were all very 

 much alike, and showed to the eye no more variation than 

 either of the parents. This conclusion is borne out by the few 

 measurements which were taken of the flowers (see Tables I. 

 and II.). The hybrids showed only a slight increase in size and 

 vigour as compared with the parents, though their sterility led 

 to much longer and more profuse flowering. The plants began 



