732 THE GENERATIVE ORGANS. 
a very clear agreement on the part of all who have investigated 
the subject that the male organ and the sting, or ovipositor, 
are homologous structures. Poulton, who has recently in- 
vestigated the development of the external organs in the 
Lepidoptera, in which the armature of the penis is but little 
developed, finds the male genital armature is represented in the 
young pupa by a single pair of papilla behind the eighth 
somite, probably my progenital somite, with a furrow between 
them, which ultimately becomes a deep pit, the origin of the 
ejaculatory duct. 
The question formerly discussed as to whether the papillz 
(rhabdites) from which the external armature is developed are 
true limbs or not, appears to me to have been completely 
settled by the observations of Dewitz, and I think the view 
held by Lacaze-Duthiers that this armature consists, in part at 
least, of the modified sterna of the genital somites must be held 
to be no longer tenable. 
ce. Comparative Morphology of the External Generative Organs. 
The parts developed by the modifications of these abdominal 
appendages have received different names in different insects. 
The anterior and posterior zygapophyses (or claspers) in both 
sexes, the valves of the ovipositor and the parts of the sting in 
female insects, and the armature of the penis of the males are 
highly modified structures formed from one or more pairs of 
these appendages. Cerci are probably also lateral ventral 
appendages of the metagenital and anal segments, but their 
development has not been traced. Lastly, the so-called podical 
plates are possibly merely divided sternal plates. 
The Anterior Gonapophyses are developed as a pair of papille 
from the posterior part of the eighth abdominal somite, my 
progenital somite. They correspond with the inferior blades 
of the ovipositor in the female of Locusta, and the great 
claspers of male Insects. They are often exceedingly complex, 
and in Tipula amongst the Diptera exhibit three distinct rami 
