Self-sterility in Dewberries and Blackberries 
15 
It will be noticed that vines Nos. 4 and 5 record absolute self-sterility; 
but this sterility is undoubtedly due to the fact that the flower buds of 
these vines were far too small when they were inclosed. The same may 
be said about most if not all of the other buds that proved to be self- 
sterile. The proper time to inclose the buds is when the pink shows 
well on the expanding petals, and about one or two days before the bud 
may be expected to open. 
Fig. 3.—Flowers of Manatee (dewberry) showing good cases of petalody. 
Knowing, then, that the parental species of our cultivated varieties 
of dewberries are either self-fertile or self-sterile, we should anticipate 
finding similar characteristics respectively in the daughter vines, and 
with few exceptions such is the case. 
The Structure of the Flower and Disease .—Petalody in the genus 
Rubus is by no means an unusual phenomenon, but when it occurs to 
such an extent and to such a high degree of development that it may 
endanger the normal functions of the essential organs of the flower, 
