24 
Siphonophora Rosarum 
features from a morphological point of view. It consists of what has 
been termed a pseudovarium, which is made up of a series of egg tubes 
arranged in two groups—one on each side of the body. 
Fig. 15. A dorsal view of the reproductive system. Semi-diagrammatic. (x 35.) 
emb. = embryos. ov. d. — oviduct. va.= vagina. vu. = vulva. 
The individual tubes of each group meet at their posterior ends, and 
each opens into a single tube or oviduct. The two oviducts—one from 
each group—join at the middle line to form a single wide canal—the 
vagina—which extends to the external aperture—the vulva—situated 
at the posterior end of the body, just below the anus. 
As the Aphis reproduces its kind parthenogenetically and vivi- 
parously in this stage of its life history, the egg tubes contain embryos 
in varying stages of develojiment. As Dufour and others have observed, 
the embryos always develop with their posterior ends pointing towards 
the mouth of the tube; consequently they are always born posterior 
end first. 
The two oviducts and the median vagina lie obliquely—dorso- 
ventrally—in the body. As it passes from the vulva, the vagina curves 
upwards until it lies just beneath the rectum. Here it divides to form 
the two oviducts, the whole taking the form of a letter Y, in the fork of 
which the rectum lies. The oviducts continue their upward course— 
the egg tubes lying mainly above the alimentary canal. 
The “ Secundare Dotter.” 
The above is the name given by the German investigators to the 
masses of granular material found in the body cavity of the Aphis and 
