1917] Goodspeed-Claiisen : F^ Species Hyhrids in Nicotiana 307 



exceedingly noticeable. The general habit of the F^ corresponds 

 exactly to that of macrophyUa, not only in the relative number of 

 laterals and the angle which they make with the main axis, but also 

 in that this main axis in both cases is short and is overtopped by most 

 of the larger laterals. 



The correspondence of the F^ flower and leaf characters with those 

 of macrophyUa as shown in plate 44, figure 1, and in plate 47, are, 

 again, too striking to warrant further comment except with reference 

 to certain specific points. Thus, the basal portion of the F^ leaf 

 compares remarkably closely with tliat of macrophyUa in the broad, 

 clasping base with rounded lobes which can hardly be called auricles. 

 In other words, the leaf-base characters of macrophyUa are near those 

 of sylvestris in the sense that they do not include the broad, clasping 

 auricles which are seen in most of the sessile-leaved Tahacum varieties 

 and yet no influence of sylvestris is here apparent. The same is as 

 strikingly true of the leaf-tip characters, since macrophyUa bears a 

 more bluntly tipped leaf than almost any of the Tahacum group and 

 is thus very near to sylvestris in regard to this character. 



In the case of the floral characters we may note first that the color 

 in Fj is nearly indistinguishable from that of the Tahacum parent, 

 being in general of a deep rose-red shade. Further, the triangular, 

 whitish areas at the bases of the sinuses are seen to correspond in 

 amount in the two flowers and add to the general color resemblance. 

 Finally, the nearly pentagonal outline of the limb in macrophyUa is 

 perfectl}^ reproduced in the F^ flowers. We have seen, in dealing with 

 FjHSG, that the limb of the angustifolia flower is much more deeply 

 lobed than that of sylvestris and here we have the macrophyUa flower 

 with practically no lobing, and thus representing the other extreme, 

 yet in both cases the F^ flowers reproduce almost exactly the shape 

 of limb characteristic of the corresponding Tahacum parent. 



FiH40 — N. Tabacum var. calycina X N, sylvestris 



This hybrid and its parents are shown in plate 39, figure 2, and in 

 plate 45. Calycina bears an unusual, rather distinctly teratological 

 flower, types of which are illustrated in plate 45. and possesses an 

 almost equally unusiud habit in tliat the laterals so much overtop the 

 terminal inflorescence that the latter is almost obscured. The flowers 

 of calycina figured in plate 45, figure 2, were selected to exhibit the 

 extreme expression of the double "hose-iu-hose" character. The 



