312 
Hermaphroditism etc. in Pediculus 
the other male organs being almost normal. Several large eggs are present, 
but they have no means of exit because all the other female organs are 
reduced to a small chitinous sack containing sensory hairs. 
(4) An hermaphrodite of intermediate type between <£ and £ (Specimen 
119, Text-fig. 20, described on p. 305) has all the female internal sexual 
organs complete, also of the male organs, a lateral half of the vesicula seminalis 
with its accessory gland, a rudimentary vesica penis and penis, but no testes. 
(5) Several £ (for example, Specimen 31, Text-fig. 12, described on p. 294) 
have the female genital organs complete besides 1 or 2 testes, there being 
no further traces of male organs. 
Relation between primary and secondary sexual characters. 
The foregoing evidence demonstrates that in hermaphrodites of Pediculus 
the state of development of the gonads, either $ or $>, is independent of the 
development of the secondary sexual organs; moreover, that the existence 
or total absence of the gonads of one sex does not necessitate the presence 
or absence of all the other sexual organs belonging to that sex 1 . On the 
other hand, the development of the external and internal parts of the secondary 
sexual apparatus appears to be more correlated. Consequently the uterus, 
with its accessory glands and vagina well developed, is usually found in 
specimens having normal external female genitalia, and, conversely, the 
vesicula seminalis, with accessory glands and normal ductus ejaculatorius, 
coexist frequently with normal external male genitalia. 
Classification of Hermaphrodites. 
It is difficult to classify our material in accordance with the systems 
proposed by different authors whose views have been collated recently by 
Cockayne (1916, pp. 76-82) 2 . Nevertheless our hermaphrodites appear to 
conform with Dalla Torre and Friese’s “ Group IV. Mixed Gynandro- 
morphism.” If Cockayne's classification is followed, then our hermaphrodites 
comprise representatives of all three groups defined as follows by this author: 
1 This is in complete agreement with the more recent evidence regarding the relation between 
the primary and secondary sexual characters, especially that afforded by the experiments of 
Meisenheimer (quoted by Kopec) and Kopec (1912). These authors removed the testes and ovaries 
from young caterpillars of Lymantria dispar which nevertheless continued to develop and gave 
rise to normal looking moths which retained their secondary sexual characters unimpaired. 
Meisenheimer, and later Kopec, transplanted testes or ovaries from one caterpillar to another 
of opposite sex, and found that the transplanted organs became connected with the sexual 
conduits of the opposite sex without influencing the secondary sexual characters of the imago. 
See Kopec, S. (1912), “Untersuchungen iiber Kastration und Transplantation bei Schmetter- 
lingen.” Arch. f. Entwickelungsmechanik, xxxiii. 1-116, pis. i-v. 
2 Cockayne, E. A. (5. i. 1916), “‘Gynandromorphism’ and Kindred Problems.” With de¬ 
scriptions and figures of some hitherto undescribed examples. Journ. of Genetics, v. 75-131, 
pis. xxi-xxiv, diagrams a-k. 
