GENITAL SYSTEM OF LYCTUS BRUNNEXJS. 583 
A block was prepared in the usual way. The sections were stained in 
Ehrlich's Haamatoxylin (f hr.) and counter-stained in Picro-nigrosin 
(30 sees.). 
Male Genital System. 
The reproductive organs are shown in PI. 31. fig. 1, and consist of the 
usual parts : testes {ts), vasa deferentia (vcf), seminal vesicles {sv), accessory 
glands (ag), ejaculatory duct (e/), internal sac, median lobe {ml), and tegmen, 
comprising the lateral lobes (II) and basal piece (bp). 
There are six testicular follicles of unequal size attached to each vas 
deferens. They occupy a large area in the abdomen from the dorsal to the 
ventral surface, and extend from beyond the basal margin of the abdomen to 
the third sternite (PL 31. tig. 5). The testicular follicles are white, rounded 
and tapering towards their apex. There is a slight cavity in the centre of 
the base of each, whence a tube arises which joins the vas deferens, which is 
of variable thickness throughout its length. In repose the vasa deferentia 
are convoluted, in parts superimposed^ and lie on the ventral surface. The 
vasa deferentia enter the seminal vesicles on their outer ventro-lateral margin 
(PI. 31. fig. 4). The seminal vesicles are joined on their inner lateral surface 
for the greater part of their length ; they are subcylindrieal and rounded at 
their apices. 
Arising from each seminal vesicle on its inner dorsal margin is a short 
tube ; these tubes meet and form the ejaculatory duct. Superimposed and 
attached to the dorsal surface of each of the two short tubes is an accessory 
gland. The accessory glands are subcylindrieal and curved, broadest 
tov/ards their base and rounded at their apices. 
The ejaculatory duct gradually tapers from its base until it enters the 
median lobe through the median foramen {mf), where it becomes hidden from 
view, emptying into the internal sac (is, PI. 31. fig. 3). (It was not found 
possible to evaginate the internal sac, nor to kill a pair of beetles in coition 
with the organs in situ ; but the internal sac was traced in sections of an 
immature male.) 
The chitinized median lobe, viewed in section, is circular at its base and 
shortly becomes elliptical ; towards its apex there arise on the upper dorsal 
and upper ventral surfaces a carina situated along the centre, with the 
internal sac lying over and on either side of the carina formed on the upjDer 
ventral surface (PI. 31. fig. 2) ; the lower or outer ventral surface is convex 
at this point. The median orifice [mo, PL 31. fig. 3) is situated a little below 
the upturned point of the median lobe. Inside the median lobe are series of 
muscles and nerve-fibres (PI. 31. fig- 2); one series of muscles is situated 
around the internal sac, others are attached to the walls of the lobe. 
Encasing the median lobe on either side are the lateral lobes, which are 
roughly semicircular in section for the greater part of their length ; they are 
42* 
