the leaf.
_Lobe_: The more or less rounded division of the leaf.
_Sinus_: The recess or bay between two lobes.
_Petiole_: The leaf-stalk.
_Petiolar sinus_: The sinus about the petiole.
_Basal sinuses_: The two sinuses toward the base of the blade.
_Lateral sinuses_: The two sinuses toward the apex of the blade.

The size, shape and color of the leaves are quite distinctive of
species and more or less so of varieties, if allowances are made for
variation due to environment. The lobing of leaves is a very uniform
character in most species, some having lobes and others having entire
leaves. The upper surface of the leaf in some species is smooth,
glossy and shiny and in others is rough and dull. The lower surface
shows similar variations and has, besides, varying amounts of
pubescence, down and bloom. In some species the down resembles
cobwebs. The number, size and shape of the lobes are important in
distinguishing both varieties and species, as are also the petiolar,
basal and lateral sinuses. As in most plants, the margins of the
leaves, whether serrate, dentate or crenate, are often distinguishing
characters. The petiole in different species varies from short to long
and from stout to slender. Lastly, the time at which the leaves fall
is often a good distinguishing mark.

_The fruit._

_Peduncle and pedicel_: Defined as in flower.
_Brush_: The end of the pedicel projecting into the fruit.
_Base_: The point of attachment of bunch or berry.
_Apex_: The point opposite the base.
_Bloom_: The powdery coating on the fruit.
_Pigment_: The coloring matter in the skin.
_Quality_: The combination of characters that makes grapes
pleasant to the palate, sight, smell and touch.
_Foxiness_: The rancid taste and smell of some grapes which are
similar to the effluvium of a fox.

Of all organs the fruit is most responsive to changed conditions and
hence most variable. Yet the fruits furnish most valuable characters
for determining both species and varieties. Size, shape, compactness
and the number of clusters on a shoot must be noted. Coming to the
berry, size, shape, color, bloom, adherence of stigma to the apex and
adhesion of fruit to the pedicel are all of value. Difference in
adherence of the skin to the pulp separates European from all American
grapes. The thickness, toughness, flavor and pigment of the skin have
more or less value. The