40 NEW YORK STATE MUSEUM 
unharmed and the flowers appeared as usual at a distance, the 
essential organs having been killed, no fruit developed.. 
Cattle sometimes browse on the twigs of thorn bushes. In such 
cases the injured branches put forth many new shoots which are 
short and dense and form an almost impenetrable surface growth. 
If the bush is low enough to be browsed from top to bottom it 
gradually assumes a conic shape. If it is so tall that cattle can 
not reach the ends of the upper branches these continue their 
normal growth and the lower part of the bush assumes a conic 
shape and the dense ramification. ~The whole bush then appears 
somewhat like two cones with their vertices united, the lower 
with its vertex pointing upward, the upper with its vertex point- 
ing downward as in an hourglass. This behavior of thorn bushes 
under the pruning given them, by browsing cattle indicates their 
suitability for hedges. 
Herbarium specimens of species of this genus should be col- 
lected at three different times. The first collection should be 
made when the plant is in flower. This collection will show the 
characters of the flowers, of the young shoots and of the young 
and unfolding leaves. The second should be made when the leaves 
have become fully developed. This will show the character of the 
mature leaves and of the young fruit. The leaves at this time are 
in much better condition than late in the season when the fruit 
is ripe. At this time it is also well to collect specimens of the 
young vigorous shoots, since the leaves on these are often larger 
and differ more or less in shape from those on older and less vigor- 
ous lateral or fertile branches. The third collection should be 
made when the fruit is ripe. Its object should be to get this in 
as good condition as possible. Insect larvae and parasitic fungi 
often injure and deform the fruit and it is well to select as far as 
possible such specimens as are most free from these pests. Some- 
times nearly every fruit on a shrub or tree is found to be injured 
by them. In some species the fruit ripens very late. In such 
cases the leaves are ready to fall or have already partly fallen 
when the fruit is ripe. Specimens bearing ripe fruit should not 
be severely pressed lest the fruit be crushed. It is well to dry 
