1917] Goodspeed-ChiKsen : F^ Species Hyhrids in Nicotiana 309 



duced late in development mar the characteristic shape of the plant. 

 The relative height of these laterals is corresponding in the hybrids 

 when at the same stage of development. 



The leaf characters of parents and hybrid are well shown in the 

 photographs and in the drawings given on plate 48. The long, droop- 

 ing leaves, rather broad in the center and tapering rapidly to either 

 end, give to "Maryland" and to the P^ a further distinct and char- 

 acteristic appearance. The correspondence in shape between the two 

 is emphasized in plate 48. The broad, clasping auricles of "Mary- 

 land" and the F, are, however, not too well figured in these drawings 

 but stand out strikingly in the photographs of plants of parent and 

 hybrid. The leaf-tip of "Maryland" is very characteristic in its 

 length and tendency to curve. The tips of the lower leaves of the 

 plants shown in plate 41, figure 1, have been broken, but the upper 

 leaves along the lower laterals bring out the character referred to, 

 while in the plants of the F^ figured both lower and upper leaves show 

 this leaf-tip peculiarity. 



The floral characters of parent and hybrid are shown in plate 44, 

 figure 2. The color of the flowers of the Tahacum parent and F, 

 hybrid is in both cases a very light pink that corresponds closely to 

 that of angustifolia and PjH36, although there is some intangible 

 difiPerence in shade of color between the two varieties and their hybrids 

 which is brought out rather sharply by a Lumiere plate. The similar- 

 ities in configuration of flower between the one parent and the hybrids 

 need no comment. Attention might be called, however, to the striking 

 likeness in calyx characters wherein size proportions are correspond- 

 ing and also to the long, shapely, pointed calyx lobes present in both 

 flowers. 



F,H179— N. Tabacum "Cuba" )< N. sylvestris 



This hybrid has been one of unusual interest in connection with 

 the inheritance of the parthenocarpic tendency exhibited In- its 

 Tahacum parent (cf. Goodspeed, 1915). As has been mentioned above, 

 the fact that all the Tabacum-sylvestris hybrids produce no good 

 pollen results in tlie falling of the vast majority of tlieir flowers, 

 usually within a day or two following anthesis. "Cuba" has been 

 shown to mature a fail' jn'oportion of fruits fi'om castrated flowers, 

 while all the othei" Tahacum varieties lose llieir flowers after castration 

 about as do the F, hybrids which lack successful pollination. In plate 

 42, figure 1, is sliown a plant of the F, hybrid made between "Cuba" 



