Lj 
No. 423.] NORTHERN POLVPETALOUS. FLOWERS. 221 
of Sorbus (mountain ash) and Crataegus (thorn) are very attract- 
ive to beetles, though often visited by flies and bees. The pear 
and apple are sought by fewer beetles and depend chiefly upon 
Hymenoptera and Diptera. The native species of apple are 
rose or pink, but readily change to white. The so-called bloom- 
less apple has small green petals resembling sepals. 
Twenty species of the Drupaceze, or plum family, are white, 
and one, the peach, is pink. The blossoms of many plums 
appear in early spring in advance of the leaves and often com- 
pletely wreathe the limbs. The flowers are visited by a great 
number of Andrenidz, and in less than two hours I collected 
one hundred and twenty specimens on a Japan plum, and these 
were but a small part of those present. 
The Mimosacez, Czesalpiniaceee, Krameriacez, and Papiliona- 
cea are often united in one family called the Leguminose, 
because the simple pistil becomes in fruit a legume. The 
Mimosa family connects the rose family with the Papilionacee. 
It is confined chiefly to the tropics, where the species are very 
numerous. The flowers are small, perfect, and regular, with the 
stamens distinct as in the rose family, or monodelphous as in the 
Papilionaceze. In the northern species the colors are white, 
yellow, or pink. The filaments are long and ciidimncian and 
are more conspicuous than the petals. 
The pea, bean, clovers, vetch, and a whole host of leguminous 
allies are grouped together in the Papilionaceze, —a name derived 
from the fancied resemblance of the flowers to a butterfly. 
Occasionally perfectly regular flowers occur by reversion, as has. 
been observed in Laburnum. For the most part, nine of the 
ten stamens unite to form a tube, at the bottom of which lies 
the honey, if present ; four of the petals interlock around this 
tube, while the fifth, called the “standard,” is broad and erect 
and bright colored to attract the attention of insects. The 
flowers are fertilized by bees, which rest upon the wing petals, 
bracing the head against the standard and bringing the ventral 
side of the body in contact with the stigma and pollen. The 
irregularity of the flowers is due to their horizontal position and 
the unequal strains to which the petals are subjected. In the 
case of certain species bees alone are able to depress the keel 
