1903] Ames,— Lobelia x syphilitico-cardinalis 285 
and measurement. The lower lip showed plainly the influence of 
L. cardinalis on the form and width of the middle lobe and the ten- 
dency of Z. syphilitica to shorten it. In the specimens studied the 
middle lobe of Z. cardina/is measured 4.5 mm. in width by r9 mm. 
in length, of Z. syphilitica 4 mm., by 12 mm., of the hybrid 4 mm. 
by 15 mm. Of the upper lip the lobes were not so divergent as in 
L. cardinalis, nor so convergent as in ZL. syphilitica, an interesting 
point to note, as it shows how far reaching are the effects of 
hybridization. 
The occurrence of scattered hairs on the corolla of the hybrid was 
of course attributable to Z. syphilitica, which has conspicuous hairs 
on the mid-veins of its corolla-lobes. ‘The corolla of Z. cardinalis is 
glabrous, and it is undoubtedly the tendency of this species toward 
glabrity which brought about the decided reduction in the number 
and length of the hairs in the hybrid. The usual effect of hybridiza- 
tion, when one parent is glabrous, is to reduce trichome structures in 
length and number, a tendency well illustrated by the case in hand 
and by Spiranthes X intermedia described by the writer in RHoDORA, 
v. 261. 
The texture, form and green of the leaves in Lobelia x syphilitico- 
cardinalis proved to be intermediate in all the plants examined; the 
surface, scabrous to the touch, indicated clearly the influence of Z. 
syphilitica and at the point of origin from the stem the leaf-bases 
were midway in their resemblance to the parent species. Although 
in outline the leaves of Z. syphilitica and L. cardinalis are quite 
unlike, it was not apparent at a casual glance just how the hybrid 
leaf resembled its parents. In the accompanying plate three leaves 
are shown which were selected at random. The one taken from Z. 
cardinals tapers gradually from the base upwards, while that of 
L. syphilitica is broadest above the middle, and conspicuously nar- 
rowed downwards. The hybrid leaf is broadest just above the mid- 
dle and tapers both ways. 
In Z. cardinalis the style closely invested by its connate stamens 
ultimately projects beyond the corolla-tube by about half its length, in 
L. syphilitica on the contrary, the style projects but slightly beyond 
the mouth of the corolla-tube. "The hybrid, however, was quite inter- 
mediate in this respect as the style exceeded the corolla-tube, at 
maturity, by less than half its length. 
None of the hybrids produced seeds naturally in the garden where 
