REPRODUCTION 461 



alimentary canal, which has been observed to be most marked 

 during the more quiescent stages of the life-history. 



The internal reproductive organs have the ringed arrangement 

 generally observed in the Arachnida. The two testes, which are 

 sometimes bi-lobed, are connected by a median structure which 

 may serve as a vesicula seminalis, and there are two vasa deferentia 

 which proceed to the intromittent organ, which is sometimes situ- 

 ated quite in the anterior part of the ventral surface, but at others 

 towards its centre. The male Mite is often provided with a pair 

 of suckers towards the posterior end of the abdomen, and some- 

 times accessory clasping organs are present. 



In some Mites there is no intromittent organ, and Michael : 

 has described some remarkable cases in which the chelicerae are 

 used in the fertilisation of the female, a spermatophore, or bag 

 containing spermatozoa, being removed by them from the male 

 opening and deposited in that of the female. The most remark- 

 able instance is that of Gamasus terribilis, the movable joint of 

 whose chelicera is perforated by a foramen through which the 

 spermatophore is, so to speak, blown and carried as a bi-lobed 

 bag, united by the narrow stalk which passes through the 

 foramen, to the female aperture. 



The ovaries are fused in the middle line, and connected by 

 oviducts with the tube (vagina or uterus) w r hich passes to the 

 exterior. There is often an ovipositor. 



Professor Gene of Turin 2 described, in 1844, some remark- 

 able phenomena in connection with the reproduction of Ticks. 

 The male Ixodes introduced his rostrum into the female aperture, 

 two small white fusiform bodies emerging right and left from 

 the labium at the moment of introduction. On retraction they 

 had disappeared. When the female laid eggs, a bi-lobed vesicle 

 was protruded from beneath the anterior border of the scutum 

 and grasped the egg delivered to it by the ovipositor, appearing to 

 manipulate it for some minutes. Then the vesicle was withdrawn, 

 and the egg was left on the rostrum, and deposited by it in front 

 of the animal. When the vesicle was punctured, and so rendered 

 useless, the unmanipulated eggs quickly shrivelled and dried up. 



Lounsbury 3 has recently confirmed Professor Gene's observation 



1 Tr. Linn. Soc. (2), v. Zool., 1890, p. 281. 



2 See account given by Tulk in Mag. Xat. Hist, xviii., 1846, p. 160. 

 3 Entomological News (Philadelphia), vol. xi., Jan. 1900. 



