242 — 



than those of H. excellens, and they have a darker hairiness; the 

 corollas are somewhat deeper yellow and the outer ones bear 

 the red stripe on the underside; the flowers are purely female. 

 Taken as a whole the hybrid origin is certain enough, but the 

 characters are unquestionably nearer H. excellens. Ripe fruits after 

 castration (No. 1J2) and after isolation (No. 145) have germinated, 

 but sparingly; at present there are 8 young plants. 

 Series V (H. excellens x pilosella). 



Another specimen of H. excellens, planted in a pot, was placed 

 in the same cold-house as mentioned above. June 16 th 1904; all 

 the opened flower-heads were removed. June 17 th ; six heads, now 

 open, were fertilized with H. pilosella, taken from the lawn near 

 the Observatory (No. 50). Harvest, sowing and planting as in the 

 foregoing series. From fruits from the crossed heads 15 plants 

 grew ; 8 were pure H. excellens, but two of them (No. 50, 9 and 

 50, io) first flowered in 1906. Among the other specimens one 

 certain hybrid did not flower in 1905 and has died in the winter 

 (No. 50, 7). Only one plant (No. 50, 4) is hermaphrodite, the other 

 hybrids are all female like their mother, perhaps with exception 

 of one, which flowered so early in 1905 that I did not happen to 

 examine it, and which has not flowered in 1906. The female 

 hybrids (Nos. 50, 1, 50,2, 50,3 and 50, s) are nearly alike: the 

 vegetative parts are strong in all respects, the flower-heads are 

 somewhat larger than those of H. excellens, but much smaller than 

 those of H. pilosella ; the heads are arranged in corymbs, usually 

 richer than the figured one (Plate I, fig. 6), which is a rather 

 slender specimen of No. 50, 3, taken late in autumn of 1905. The 

 undersides of the leaves bear a poor covering of stellate hairs, but 

 do not get the whitish aspect of those of H. pilosella. Generally 

 speaking the hybrids are nearer to H. excellens than to H. pilosella. 

 Offspring of some of them are now in the Garden, but will first 

 flower next year; the figured plant has given rise to two plants 

 after castration (No. 147), and others are produced from not-isolated 

 fruits of the same plant (No. 120) and of another, No. 50, 2 (No. 

 1 17). The fruiting-power is rather small ; during the second flowering 

 in 1905 two castrated heads of the hermaphrodite specimen (No. 50, 4) 

 gave no full fruits ; five castrated heads of the female No. 50, 3 

 gave 15 full and 142 barren fruits, while isolated heads of the 

 same plant gave 7 full and 350 barren fruits. 



The experiments have at present reached this point, but wiien 



