84 BULLETIN OF WISCONSIN NATURAL HISTORY SOCIETY. VOL. 1, NO. 2. 
the Muacidae, Anthomyidae and Scatomyzidae are frequently 
observed on the willow-catkins, and most certainly contribute their 
modest share of work •in effecting pollination. The smaller flies 
of the families Phoridae, Sepsidae, Oscinidae and others visit the 
flowers in search of nectar, but can not be relied upon to render 
eflicient services, as, on account of their small size, they can crawl 
down to the nectarglands, without necessarily coming in contact 
with either the anthers or the stigmas. 
This same consideration applies to the small-sized species of 
beetles and bugs, Avhile the large species of these orders, as well 
as the butterflies, may be expected to carry pollen to the stigmas, 
if they visit the flowers in the appropriate order; that is, if they 
visit the staminate catkins in advance of the pistillate. The stami- 
nate catkins, with their numerous yellow anthers, are undoubtedly 
more conspicuous than the pistillate and, besides, they offer both 
pollen and nectar to the visitors and may, for these reasons, be ex- 
pected to be more attractive to insects than the pistillate catkins, 
which are provided with nectar only. Observations establish the 
fact that insects are more numerous on the male (staminate) 
flowers than on the female, and there is a probability of the 
visitors paying their attention to the male flowers before visiting 
the female. 
Before closing these remarks on Salix discolor and the throng 
of insects feasting on the sweets of its flowers, it remains for me 
to state, that the latest flowers of this species may be observed in 
the first week of May, and that, during its blooming period, 
several other entomophilous flowers make their appearance, as for 
example additional species of Salix, two species of Hepatica, two 
species of Erythronium, Dirca palustris, L., Sanguinaria .cana- 
densis, L., Claytonia virginica, L. and Isopyruni hiternatiini, T. 
ik G. Although, as the season advances, anthophilous insects be- 
come more numerous, yet competition among the gradually in- 
creasing number of entomophilous plants becomes more severe, 
and accordingly the blossoms of Salix discolor are not visited so 
abundantly towards the end as during the first and second week 
of its blooming period. 
