200 THE AMERICAN NATURALIST. [Vor. XXXV. 
street flower-venders. In S. candida and. S. purpurea the 
anthers are red, and in the former the style is also dark red; 
but usually the anthers are yellow. The scales display con- 
siderable range in coloration; in S. purpurea and several other 
species they are purple; in S. nigra, yellowish ; in S. myrtz/- 
loides, greenish-yellow, capsules reddish-green ; in S. uva-ursi 
the scales are rose red at the tip; in S. humilis and SS. tristis, 
dark red or brownish. The twigs also vary much in color; as 
green, white-woolly, yellow, brown, red, crimson, and purple. 
The willows are very attractive to insects and on a warm day 
they may be observed hovering in clouds about the bright yel- 
low sprays of bloom. The pistillate aments are not so con- 
spicuous as the staminate, and in the case of S. discolor attract 
a smaller number of visitors. On the flowers of this plant I 
have collected five bees, nine flies, and two beetles. Species 
of Andrena, seeking food for their young, and flies are very 
common. 
The inflorescence of the Betulaceze, birch family, is ane- 
mophilous, and usually moncecious There is no corolla. In 
Carpinus, Ostrya, and Corylus the calyx is present in the pis- 
tillate flowers but wanting in the staminate; conversely, in 
Betula and Alnus the staminate flowers have a calyx and the 
pistillate have not. Originally the calyx was doubtless present 
in both forms. Its presence or absence in the one sex or the 
other of the different genera has been largely influenced by 
mechanical conditions. In the fertile flowers of the hornbeam, 
hop-hornbeam, and the hazel there are but few blossoms in the 
capitate inflorescence, while the sterile flowers are more densely 
aggregated. An opposite condition prevails in the birch and 
alder, where, though both kinds of aments contain numerous 
flowers, they are more densely aggregated in the fertile than in 
the sterile. Where declinic flowers are solitary, or few in a 
cluster, as in Fagus, Castanea, Asparagus, and Ribes nigrum, 
both forms possess a perianth. The hazel (Corylus) derives its 
English name from the color of the nuts, as “in hue as hazel- 
nuts," Shakespeare, 7; aming of the Shrew, II, 1.1 The stami- 
nate aments are yellow, and in autumn the leaves also become 
1 Enc. Brit., vol. xi, P- 548. 
