ORGANS FOR SPERM-TRANSFER 261 
row, but there is no movable joint. The organ is more pointed 
and the groove is very deep from the rising up of its sides. Thus 
in section fig. 19, the narrow median mass, (M.m) to the left, 
rises high up beyond the groove and the groove itself is a narrow 
space between the wide external and the narrow median masses. 
In the surface view, (fig. 18) the bottom of the groove is indicated 
by the broken line; it is already twistetl so that the groove looks 
towards the median side along its proximal part and then for a 
short distance toward the observer, that is toward the ventral 
side, and finally at the tip toward the median side again. Where 
the groove is open ventrally the median mass is rising up as a 
protuberance that will form the spatula. As yet the canula is 
only the spoon-shaped end of the organ. 
In a male 22 to 21’mm. long and probably in the sixth stage, 
(fig. 20) killed October 4th, we find the same stage as in other 
males of this size killed in July, this being an exceptional male that 
failed to grow as the average do to be nearly two inches long in 
October. Here the spatula is quite evident as a blunt rounded 
finger-like elevation that crosses over the groove. As shown by 
the dotted line the bottom of the groove is to the right of its mouth 
along the proximal part of its course and to the left along under 
the base of the spatula; that is, the sinuousness of the groove. is 
exaggerated by the fact that the sides not only rise up but grow 
over the groove, the external mass overhanging toward the medi- 
an line proximally and the median mass growing over away from 
the median line, distally. The base of the stylet now bears a few 
short acicular setae and is provided with three muscles at its at- 
tachment to the sternal elevation upon which it stands. By this 
time the stylets point forward under the thorax. The canula is 
now a short rounded blunt termination of the stylet in which the 
groove is no longer widely open but reduced to a slit by the up- 
growth of its walls. 
In an autumnal male 38 mm. long, (fig. 21) the stylet has be- 
come much longer and more modeled but still shows the stiff 
joint between the base and the partly-formed neck. The few 
setae extend along the ridge of the base on to the proximal part 
of the external mass. The median mass sticks out abruptly at 
