1^--] Seichell-Goodspced-Clausen: Nicotiana Tahacum 467 



2. Fi OF THE ANGUSTIFOLIA-MACROPHYLLA SERIES 



In late July of 1909, some 7 crosses were made between angusti- 

 folia and macrophylla, 6 of which, as stated above, were successful. 

 Hj, H^, and H,, as they were designated, involved angustifolia as the 

 female plant, while H4, H5, H15, and H^g were reciprocals. No seed was 

 obtained from H^, but all the other 6 crosses gave a fair yield. The 

 usual care (cf. Goodspeed, loc. cit., pp. 129-131) was taken in cleaning 

 and sowing the seed. This was done in the spring of 1910, germination 

 was good in all cases, and 337 plants, distributed as follows, came to 

 maturity and seed bearing. The family of H„ had 56, H3 had 60, H^ 

 had 47, H^ had 58, H^j had 55, and Hig had 61 plants. 



A survey of all these plants showed in general a remarkable uni- 

 formity in habit. A certain amount of difference was to be detected 

 on careful scrutiny, but little if any greater than that which is ex- 

 hibited among a large number of individuals of one or the other parent. 

 In height, F^ showed exactly the same variation as the parent, the 

 central axes varying from 65 to 145 cm., but largely varying from 90 

 to 120 cm., while the laterals rose to 150 cm. Some rows showed uni- 

 formly higher, others uniformly lower plants, the differences probably 

 being due to different soil and water conditions. The habit (see pi. 61) 

 was low corymbose and the general appearance as to stoutness seemed 

 more or less intermediate between the two parents. The leaves in 

 shape, size, etc., very closely resembled those of angustifolia. There 

 was some appreciable variation in the leaves, however, and often con- 

 siderable variation on the same plant, a characteristic of angustifolia 

 which has already been mentioned. Plate 59 reproduces photographs 

 of different types of leaves obtained from F^ plants. The blade is 

 broadly elliptical ovate with the lateral veins at an obtuse angle, much 

 as in macrophylla. The base is rounded, or even slightly cordate in 

 some leaves, while the tip is more blunt. These characters seem, at 

 least, to' indicate an influence of macrophylla. The leaf, however, is 

 distinctly petiolate, but the petiole is not so long as in angustifolia. 



The petiole is definitely winged and the wings are expanded at the 

 base into auricles, which are often triangularly decurrent along the 

 internode of the stem. This wing is usually present in all the plants 

 of Fj, but some leaf or leaves on a plant may lack it, and in some 

 plants it is only slightly developed, or at least, is without auricles. 

 The wing was from 5 to 7 mm. wide on some leaves. 



The leaf of lOF^Hi^P^ represented in plate 62 even more closely 

 resembles the typical leaf of angustifolia. The wing along the mar- 



