ton
Lutie
Moore Early
Poughkeepsie
Pocklington
Prentiss
Rochester
Senasqua
Winchell

CLASS II. Clusters marketable; moderately compact or loose.

Agawam
Brilliant
Brown
Catawba
Champion
Chautauqua
Clinton
Colerain
Concord
Dutchess
Early Victor
Elvira
Empire State
Fern Munson
Hartford
Iona
Isabella
Isabella Seedling
Jefferson
Jessica
Lady
Mills
Missouri Riesling
Perkins
Rommel
Triumph
Ulster

CLASS III. Clusters unmarketable.

Brighton
Canada
Dracut Amber
Eumelan
Geneva
Hayes
Lindley
Noah
Northern Muscadine
Vergennes

CLASS IV. Self-sterile. No fruit develops on covered clusters.

America
Aminia
Barry
Black Eagle
Clevener
Creveling
Eldorado
Faith (?)
Gaertner
Grein Golden
Hercules
Jewel
Massasoit
Maxatawney (?)
Merrimac
Montefiore
Requa
Salem
Wyoming

In the main, the cause of infertility, as with other fruits, is the
impotency of pollen on the pistils of the same variety. There are a
few cases in which pollen does not seem to be formed abundantly, but
these are very few. There are a few cases, also, in which the pistil
does not become receptive until after the pollen has lost its
vitality; these, however, are very few. In a greater number of cases
the pollen is found defective. However, dismissing all of these as the
exception, the rule is that self-sterility is due, as has been said,
to the lack of affinity between pollen and pistils produced on the
vines of some varieties.

Nature is helpful to the grape-grower in giving a guide to
self-fertility. The length of stamens is a fairly safe indication of
self-fertility. All grapes which are self-fertile bear flowers with
long stamens, although the latter are not a sure sign of
self-fertility, as a few varieties with long stamens are self-sterile.
On the other hand, short or recurved stamens are always associated
with complete or nearly complete self-sterility.

The remedy for self-sterility is inter-planting. Only the varieties
named in Classes I and II in the foregoing classification should be
planted alone. The sorts named in Classes III and IV must be planted
near other sorts which bloom at the same time in order that their
flowers may be cross-pollinated.