26 
Regeneration in Ticks 
nature where they are frequently injured through their forcible removal from 
the host, the hooked hypostome and digits of the chelicerae being broken off 
to a varying degree because they are so firmly anchored in the host’s skin. 
Such mutilation of the mouthparts is much more likely to occur in Ixodid 
than in Argasid ticks because the mouthparts of the latter are as a rule less 
effective anchoring organs, the structure of the mouthparts in the two groups 
being correlated with their feeding habits upon the host. 
Regeneration of legs. 
The experiments with Argas persicus herein recorded confirm those of 
Hindle and Cunliffe ( loc . cit.). If the legs of the larva are amputated shortly 
after the tick has abandoned the host in a fully gorged condition, the first- 
stage nymph usually shows stumps corresponding in length to the portion 
of limb that was left intact in the larva. The authors cited found, however, 
that if the larva had its legs amputated whilst attached and feeding on the 
host, i.e. 2-3 days prior to its dropping off in a replete state, that the legs 
may at times be regenerated in which case they are usually of subnormal 
size. When the legs of first and second-stage nymphs are amputated soon 
after they have fed, the limbs are regenerated but are usually small. Immature 
ticks with small or stumpy legs, if not subjected to further interference, de¬ 
velop normal limbs after a further moult. . > 
My experiments with A. hebraeum and H. aegyptium show that these 
Ixodid ticks possess greater powers of regeneration than A. persicus in respect 
to the legs, this being in harmony with the results above described in con¬ 
nection with the mouthparts. The number of legs amputated from the two 
Ixodid species in the larval and nymphal stages was 21 and all of them were 
regenerated; 13 limbs were of normal size and 8 slightly smaller than normal. 
