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BULLETIN OF WISCONSIN NATURAL HISTORY SOCIETY. VOL. 2. NO. 1. 
be considered in the course of this paper, with the same points in 
view as in the case of the Smilax-species. 
The flowers of the latter have a greenish color. In a paper on 
the pollination of the greenish-yellow flowers of plants belonging 
to the genera Caulophyllum, Ptelea, Rhamnus, Rhus and Sassa- 
fras, Robertson (2) reviews the opinions held by various authors 
on the effect of the greenish color of the flowers on the insect- 
visitors. According to Delpino and Herm. Mueller, such flowers 
are very attractive to the larger flies (macromyiophilous), but 
the observations of Robertson show a distinct predominance of 
the flies in one species only, in Sassafras officinale, Nees, while in 
the remaining species (with the exception of Caulophylhtm thalic- 
troides (L.) Michx.), the lower bees, Andrenidae are the leading 
visitors. Of the dark colored flowers, such as are present in our 
Waahoo, (Euonymus atropiirpureus) Delpino and Herm. Muel- 
ler express the view that they are visited mostly by flesh-flies 
(sapromyiophilous). As will be shown later on, the observations 
made on the Waahoo do not support this view. 
SMILAX L. 
The plants are dioecious, and produce simple flowers, which, 
in our own three species, present a very slight variation in struc- 
ture, size and color. The staminate, as also the pistillate flowers, 
are gathered in axillary umbels and have a greenish-yellow color. 
In the staminate flowers the perianth-segments and stamens are 
present to the number of six, rarely of eight, and honey is se- 
creted around the base of the filaments, as also along the inner 
surface of the perianth-segments. The pistillate flower has the 
same number of perianth-segments as the staminate, and contains 
an egg-shaped ovary, crowned with a three- or rarely a four- 
parted stigma. In addition to these parts it has abortive stamens, 
consisting of small filaments without anthers, which are appressed 
to the ovary, and never spread, as they do in the staminate flow- 
ers. The secretion of honey around the base of the ovary, and on 
the inner surface of the perianth-segments, is about the same as in 
the staminate flowers. The abundant whitish pollen of the stam- 
inate flowers renders the latter more conspicuous than the pistil- 
late flowers, in which all the parts are of a greenish color. 
The characters mentioned above are those common to all three 
of our species. 
(2) Chas. Robertson, Flowers and Insects, XVII, Bot.Gaz., Vol. XXII (1896), 
pp. 154-165. 
