190 University of California Piiblications in Botany ["^"ol. 5 



191.0 crosses. 

 H33 — X. sylvestris X X. Tabacuni var, macrophylla purpurea. 



H34 — ]S. Tabacum var. macrophylla purpurea X X. sylvestris. 

 1911 crosses represented this year (1912) by Fj plants. 



H3o— X. sylvestris X X. (Tabacum) angustifolia (U. C. B. G. 68/07) 

 (Setchell, p. 9). 



H36 — X. (Tabacum) angustifolia X X. sylvestris. 



H38— X^ Tabacum var. macrophylla (U. C. B. G. 22/07) (ibid., p. 8) 

 X X. sylvestris. 



H40— X. Tabacum var. calycina (U. C. B. G. 110/05) (ibid., p. 6) X X. 

 sylvestris. 



H41— X. sylvestris X X\ Tabacum "Maryland" (U. C. B. G. 78/05) 

 (ibid., p. 5). 



H43 — X. sylvestris X the Fi hybrid— X. Tabacum ' ' Maryland "XX. 

 Tabacum "Cavala" (U. C. B. G. 72/05) (ibid., p. 5). 



H44— The F^ hybrid— X. Tabacum "Maryland" X X. Tabacum "Cav- 

 ala ' ' — -X X. sylvestris. 



H45 — X. sylvestris X the Fj hybrid — X. Tabacum "Maryland" XX. 

 Tabacum ' ' Cavala. ' ' 



A detailed report upon these 1910 and 1911 F^ hybrids is in 

 preparation and it will only be said here that the 1911 F^ hybrids 

 duplicate in general the increase in vegetative and floral develop- 

 ment noted for the 1910 series. 



As will be noted in the above the reciprocals of only two of 

 the five 1911 crosses were represented in the field in 1912. In 

 the other cases viable seed was not obtained. This fact and the 

 germination of the seed resulting from the various crosses made 

 in 1911 are of interest in connection with certain results noted 

 in a recent paper by East and Hayes {loc. cit., p. 28). As will 

 be seen there the seed produced from 18 crosses between Nicotiana 

 species and between Nicotiana varieties which list includes the 

 cross ''N. sylvestris Speg. and Comes X A. Tahacum L." and its 

 reciprocal — germinated to the extent of 100 per cent. Which 

 one of the numerous A. TaftacMm-varieties was employed in this 

 cross with X. sylvestris is not stated, but of the four varieties 

 used in our crosses made in 1911 it is doubtful whether under 

 the conditions employed in our cultures (Goodspeed, 1912, p. 

 132) — and these are the conditions commonly available in similar 

 work — the seed resulting from any of these crosses of ours ger- 

 minated to the extent of 100 per cent. Results are at hand for 



