1913] Goodspeed: Nicotiana Hijhrids 195 



sylvcstris X F^ of the cross i\". Tahacum "Maryland" X N. 

 Tahacum "Cavala," it is interesting to note the partial report 

 in the Gardner's Chronicle (vol. 50, 3d series, p. 309) of infor- 

 mation, in connection with similar hybrids, given before the 

 Fourth International Congress on Genetics by M. C. Bellair, 

 Head Gardener at the National Palaces — ''N. sylvestris pol- 

 linated by T. (sic!) Tahacum gives an F^ generation exhibiting 

 in many respects the characters of the latter species.* The 

 Fn germination yields a number of types of which some were 

 fertile and some sterile. In Fg plants resembling the two 

 parents were obtained. When crossed with one another they 

 produce a large series of forms — giants, dwarfs, white, rose, 

 red colored and striped Howers. " No mention is thus made 

 of sterility in F^. The X. Tahacum used in ^Ir. Bellair 's cross 

 is not made plain. In this connection it is to be noted that 

 in certain F^ plants produced from the seed of crosses H43, 

 H44, and II45 a considerable quantity of what appears to 

 be normally developing seed is forming. Though mature seed 

 capsules at the present time are not obtainable, partially mature 

 capsules borne on one plant of cross H45 exhibit from 30 to 50 

 seemingly normally developing ovules on the placentae. The 

 flowers on this plant persist to a much larger extent than in the 

 case of any of the other F^ hybrids, no early browning of the 

 placentae takes place, and in general this plant may be expected 

 to yield a rather large quantity of seed, some of which should 

 be viable. Of the 27 F^ plants produced from the seed of this 

 cross three or four almost exactly typical N. Tahacum "]\Iary- 

 land" individuals are present while the remaining 24 or 25 plants 

 seem to exhibit a blending of the characters peculiar to the two 

 Tabacum varieties involved in its pedigree. The plant refered to 

 above which seems to be producing an unsual quantity of seed 

 is of this blended type. The three F^ plants nearly identical with 

 the N. Tahacum "]\Iaryland" parent also seem to be producing 

 flowers which in certain laterals are persisting much longer 

 than in the case of the other .Y. Tahacum-varieties X X- sylvcstris 

 hvbrids and longer than the flowers in the case of the 23 or 24 



* A similar degree of dominance of the N. Tabacum-varieties has been 



tlirouijliout observed in imi- cultures. 



