L. E. Kobinson and J. Davidson 
421 
EXPLANATION OF PLATES XXV TO XXVIII. 
PLATE XXV. Argas persicus. 
The muscular system of the male as displayed after the removal of the dorsal integument 
and the viscera. Magn. 25 diam. 
PLATE XXVI. Argas persicus. Female. 
Fig. 1. The genital organs from the dorsal aspect. This figure shows the condition of 
the genitalia just before the commencement of oviposition and should he compared 
*■ with the earlier condition illustrated on Plate XIV, Part II. Magn. 25 diam. 
Fig. 2. Transverse section of the ovary of an unfed female, showing the ovarian epithe¬ 
lium with ova (o. o'.) in various stages of development, and the ovarian gland (gl. ov.). 
Magn. 125 diam. 
Fig. 3. Transverse section of the ovary at the place of origin of the oviduct. The 
youngest ova (o.) are still completely embedded in the thickness of the ovarian 
epithelium, while the more mature ova (o'.) lie without the wall of the ovary, to 
which they remain attached by the pedicels (p. ov.). Magn. 125 diam. 
Fig. 4. Section of a portion of the wall of the ovary in a very young female (deutero- 
nymph ?), showing the earlier stages in the development of the ova. Magn. 1000 diam. 
Fig. 5. Transverse section of the ovary at a late stage, with two large ova lying free 
within the lumen of the ovarian tubule. It may be observed that these ova are still 
unprovided with a shell. Magn. 60 diam. 
Fig. 6. Terminal portion of the genital tract as seen in dissection from the right side. 
Magn. 25 diam. 
Fig. 7. Median longitudinal section of the cervical portion of the vagina, showing its 
relations with the uterus and the vestibular portion of the vagina respectively. 
Magn. 200 diam. 
Fig. 8. Gene’s organ. The saccular portion in the non-active condition. The eversible 
cliitinous sacs ( ct. s.) are seen to be suspended within the hypodermal sacs (hd. s.\. 
The wide efferent ducts of the glands are represented in plain outline. Magn. 36 diam. 
Fig. 9. Gene’s organ. Transverse section of the posterior part of the saccular portion, 
showing the internally situated chitinous sacs (ct. s.) and the enveloping hypodermal 
sacs (hd. s.); also the situation of the organ in relation to the shafts of the chelicerae. 
Magn. 140 diam. 
Fig. 10. Gene’s organ. Section through one of the lobes of the glandular portion, 
showing the secretory cells. - Magn. 485 diam. 
PLATE XXVII. Argas persicus. Male. 
Fig. 1. The genital organs from the ventral aspect. Magn. 35 diam. 
Fig. 2. The genital organs from the lateral aspect: the testis and the upper part of the 
vasa deferentia have been removed. Magn. 47 diam. 
Fig. 3. Transverse section of the genital tract at the place of communication between 
the seminal vesicle ( v.d.c .) and the ductus ejaculatorius (c. g. com.), showing the 
constricted proximal portion of the latter, into which the ducts of the accessory 
glands open. Magn. 260 diam. 
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