542 SIDNEY I. KORNHAUSER 
two changes both authors agree: the reduction of the scopa of 
the female and the assumption of the male color for the clypeus 
of the female in Andraena chrysosceles and Andraena, labialis. 
Stylopized males show no reduction of the testes and may have 
functional sperm; but in the female the ovary, which is normally 
a hundred times the size of the testis, is greatly reduced through 
lack of nourishment and produces only minute functionless 
eggs. Smith seizes upon this fact as the cause for the changes 
wrought in the female characteristics. He argues that, as in 
birds (Goodale, ’16) the ovary inhibits the development of male 
characteristics, so also in Andraena the absence of the ovary 
allows the male characteristics to develop. This assumption 
will be considered later. 
Most closely associated with the study undertaken in the 
present paper is the work of Giard (’89). He described the 
effect of the internal parasitic dryinid, Aphelopus melaleucus, 
and the parasitic dipteran, Atelenevra spuria, on the homopterans 
Typhlocyba hippocastani and Typhlocyba douglasi. In females 
of both species of Typhlocyba infested with Aphelopus, the 
Ovipositor was much reduced. Atelenevra had much less effect 
on this organ. In Typhlocyba hippocastani the oedagus is a 
complicated forked organ, and this is greatly altered by the 
parasites, the forks being reduced from eight branches to six, 
four, or even three. In the males of both species there occurs 
on the ventral wall of the abdomen a pair of organs of unknown 
function, perhaps homologous with the sound-producing appa- 
ratus of male cicadas. Ordinarily, these extend from the first 
to the posterior extremity of the fourth somite. In parasi- 
tized males these enigmatical organs seldom reach beyond the 
middle of the first somite, being reduced to two small pockets. 
Matausch (’09, ’11) described the effect of insect parasites on 
Membracids. In his first paper he believed that he was dealing 
with gynadromorphs, but later (11) discovered that the abnor- 
malities were caused by parasites. 
Changes similar in character, but even more striking than 
those described in the insects, have been studied in crabs infected 
with rhizocephalans, parasitic barnacles. Giard (’86, ’87 a, ’87 b, 
