412 
Argas persicus 
capsule of the tubule. The nuclei of the secretory cells are moderately 
large and rich in chromatin, and are generally situated near the central 
portion of the cell. The cytoplasm is pale and shows a coarse reticulum 
of spongioplasm, the interstices of which are filled with the hyaline 
fluid secretion. The mouths of the gland tubules open collectively 
into a broad duct which runs towards the middle line of the body, 
and, as shown above, communicates directly with the cavity of the 
hypodermal sac. 
Nuttall has described and figured the operation of oviposition in 
Haemaphysalis punctata 1 and there is every reason for believing that 
the operation is very similar if not quite identical in Argas persicus. 
The chitinous sacs are presumably everted by the rapid secretion 
of fluid by the glands of Gene’s organ, which fluid pours into the space 
between the chitinous and the hypodermal sacs. The chitinous sacs 
are ballooned out until their walls become quite tense, and the secre¬ 
tion, which serves to moisten the ova, presumably with the object 
of preventing or delaying desiccation, percolates through the thin 
membranous chitin. We have never seen the sacs in the everted 
condition in Argas persicus , and are unable to say whether the secre¬ 
tion transudes through the actual substance of the chitin, which, it 
may be remarked, is excessively thin, or whether the chitin is 
perforated by minute pores such as appear to be scattered over the 
surface of the everted sacs in Haemaphysalis punctata. It is impossible 
to distinguish such pores in the collapsed state of the sac. 
How the everted chitinous sacs are withdrawn into the hypodermal 
sacs during and after the act of ovijiosition, it is not easy to explain. 
So far as we have been able to observe, they are not connected with 
any part of the hypodermal sacs, except at the external opening of the 
organ. The rhythmical movements of the everted sacs, which are 
exhibited during the act of oviposition, may be brought about by 
the contractions of the muscles which are attached to the proximal 
extremity of the hypodermal sacs, and we can only suggest that 
the natural elasticity of the S-shaped longitudinal folds, together with 
the action of these muscles and the absorption of the residual fluid 
remaining in the space between the chitinous and hypodermal sacs, 
helps to bring about the re-invagination of the chitinous sac -and its 
restoration to the normal resting position. 
1 Nuttall, G. H. F, (vii. 1908), pp. 16, 17 repr. 
