206 REPORT OF THE CONFERENCE ON GENETICS. 
Rusus Hyprips. 
The Logan-berry. 
It has long been known that Rubi intercross in the field with great 
readiness. The difficulty in assigning wild forms to their systematic position 
bears this out. 
Perhaps the hybrid of most interest to horticulturists is the Logan- 
berry, the reputed result of a natural cross between Rubus ursinus and 
f. Ideus var. The logan-berry scarcely needs description. It is to all 
appearance a bramble, the influence of the raspberry parent being 
evidently slight. One of the most noteworthy characters of this plant 
is its fertility. Its seedlings grow as readily as weeds. With me, they 
show no trace of the raspberry, but repeat the logan-berry. Amongst 
minor variations are the form and size of the flower and lessened fruit- 
production. Some of the seedlings, however, prove to be as good 
bearers as the parent. 
The seedlings of the second generation do not in general vary any more 
than those of the first generation. One plant, however, in a set of over 
twenty seedlings from a free-fruiting seedling of logan-berry has ben 
found to be indistinguishable in habit, stem, and foliage from the garden 
raspberry. It is very vigorous. The strongest stems are 7 feet in length, 
and stand erect without support. Unfortunately, no notes have been 
made of the fruit borne by this plant; but there seems no reason to 
suppose that it is a chance seedling raspberry. 
Raspberry x Logan-berry. 
Seeing that it is understood that the raspberry is one of the pirents of 
the logan-berry, it is interesting to note the peculiarities of hybrids 
between the raspberry and logan-berry, the latter being the pollen- 
parent. 
Nine plants with this parentage have been grown for a long enough 
time to bring out their characters. Most of them are much alike. They 
all show the blending of the raspberry and the bramble habit. One plant 
is distinct from its neighbours, its foliage being more pointed, and the 
venation more sharply defined. It is far more floriferous than the others, 
and has borne a very heavy crop of fruit. The fruit (fig. 48 6) was interest- 
ing in showing a compromise in the core, between the conditions seen in 
the bramble and the raspberry. When the fruit was pulled (fig. 48 a) one 
found that the cap of drupels did not separate from the core (torus), the 
terminal half of the core being attached in a certain degree to the drupels, 
although by no means so firmly as in the bramble. 
The plants do not show any appearance of true raspberry characters, 
such as might have been expected if the parentage of the logan-berry is 
what it is stated to be. 
Rubus occidentalis x R. rosefolius (syn. R. sorbifolius). 
Rubus occidentalis, the blackcap or thimble-berry, is a tall-growing - 
shrubby species, reaching the height of 7 feet. The stems are coated 
for a foot or two from the ground with a purplish-glaucous bloom. 
