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Wallace, Alfred Russel, 1823-1913

"Darwinism (1889)"


Ovaries, a single pair in segment 13.
Oviducts open by a common pore in the middle of segment 14.
Vasa deferentia open separately in segment 18, each furnished at
its termination with a large prostate gland.

Between two and three hundred specimens were examined, and among them
thirteen specimens exhibited the following marked variations:--

(1) The number of the spermathecae varied from two to three or
four pairs, their position also varying.
(2) There were occasionally two pairs of ovaries, each with its
own oviduct; the external apertures of these varied in position,
being upon segments 13 and 14, 14 and 15, or 15 and 16.
Occasionally when there was only the normal single oviduct pore
present it varied in position, once occurring on the 10th, and
once on the 11th segment.
(3) The male generative pores varied in position from segments
14 to 20. In one instance there were two pairs instead of the
normal single pair, and in this case each of the four apertures
had its own prostate gland.


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