30 
N. C. Agricultural Experiment Station 
From a study of tlie above tables we come to tlie following conclusions: 
first, that tlie pollen from the self-fertile varieties of Rubus villosus 
can fertilize tlie flowers of other self-fertile varieties of the same 
species; second, that the pollen from self^fertde varieties of Rubus 
villosus can fertilize the flowers of self^erlile varieties of the same 
species, and also, with the exception of the variety Manatee, those of 
the self-sterile species, Rubus trivialis; third, that Fig, pollen from the 
selfi-ekiie- variety Premo can fertilize the self-^tertfe varieties of the 
same species, and, with the exception of Manatee, the self ^ertilo varieties 
of Rubus trivialis ; fourth, that the self-sterile varieties of Rubus 
trivialis can fertilize all varieties of Rubus villosus and, with the variety 
Manatee excepted, the self-sterile varieties of Rubus trivialis and their 
hybrids; fifth, that the pollen from a self-sterile variety cannot fertilize 
the flowers of the same variety. 
Consequently, the very interesting fact becomes evident that self- 
fertile varieties are not the only ones that can be used successfully as 
pollinators in a berry plantation, but that so far as viability of the 
pollen and fertilization is concerned, we can also use the recognized 
self sterile varieties. This fact, with the exception of Manatee, holds 
true, even though all of the varieties that are to be pollinated are 
self-sterile. 
The variety Manatee presents a very unique case, and requires some 
words of explanation. From the information gained in Table No. 1, we 
learn that Manatee is practically a self-sterile variety. Frequently, how¬ 
ever, under certain conditions of self-pollinal ion, one to several druplets 
will be produced and will ripen. This condition, as has previously been 
stated, appears to be the result of self-fertilization. Other varieties of 
Rubus trivialis frequently behave similarly. 
Manatee, when crossed with other varieties, behaves variously: gen¬ 
erally speaking, it will not set much, if any, fruit when crossed with 
pollen from the self-sterile varieties of Rubus trivialis. When crossed 
with pollen from the self-fertile varieties of Rubus villosus some fruits 
will develop; but with us, Manatee growing in a mixed plantation never 
has set a paying crop of berries. As a pollinator for other varieties,, 
therefore, Manatee is worthless, because the percentage of defective 
pollen produced by its flowers is so great that in a large berry plantation 
a dearth of viable pollen would be the result. 
As has already been mentioned, the pollen of Manatee seems not to 
be very acceptable to floAvers of other varieties of Rubus trivialis, for 
while in some years fairly good fruit was obtained in the hybridizing 
tests, yet in other seasons the resultant fruit crop was exceedingly poor, 
and in some cases no fruit at all was obtained. Neither is it very accept¬ 
able to varieties of Rubus villosus. Lucretia, Austin, Premo, and the 
self-fertile hybrids, Cox and Ruth, when pollinated with Manatee, show, 
varying results. Of the varieties mentioned, Ruth seems to be able to use 
Manatee pollen to the best advantage, for the resultant fruit seems quiie 
