E. Hindle and N. Cunliffe 
361 
From these results it seems that a period of at least nine days 
must elapse between the amputation and moulting. Even with this 
period, however, some individuals showed no signs of regeneration, whilst 
others only developed very imperfect appendages. 
We should like to call attention to the case in which, although only 
the second and third legs of the right side were removed, yet in the 
nymph the first right leg was reduced in size as well as the regenerated 
appendages; all the left legs and also the fourth right leg were of 
normal size. 
First Stage Nymphs. 
Since all stages of A. persicus, excepting the larval stage, usually 
feed to repletion within half-an-hour, the time between feeding and 
amputation can be determined exactly, and it will be noticed that the 
results of this series of experiments are much more uniform than in the 
case of those with the larvae. 
Experiment 7. A batch of first stage nymphs was fed on De¬ 
cember 9. The following day the four or five distal articles of the 
second right leg were removed, the ticks being kept at a uniform 
temperature of 37° C. At the same time an equal number of the same 
batch of nymphs were kept as control in order to see whether the 
amputation delayed the subsequent moulting. 
Of the amputated ticks, one moulted on 16. XII. 12, four on 
17. XII. 12, and six on 18. XII. 12. In every case, all the articles of the 
appendage were regenerated and the leg was of normal proportions, but 
the size was only two-thirds to three-quarters that of the corresponding- 
leg of the opposite side. Of the controls, seven moulted on 16. XII. 12, 
and four on 17. XII. 12. It seems therefore that amputation may 
slightly delay the subsequent moulting. 
Experiment 8. A batch of first stage nymphs was fed on April 2, 
and then divided into groups of six, in each of which different legs or 
different articles were amputated. In every case the ticks were kept 
at 30° C. The results are given in tabular form. 
(a) Claws of second right leg amputated 3. IV. 13. 
14. iv. 13 
15. iv. 13 
17. iv. 13 
19. iv. 13 
2 moulted 
2 
1 
1 
5 5 
55 
55 
Regeneration perfect. 
55 55 
5 5 5 5 
5 5 5 5 
This experiment was undertaken especially to determine whether 
the regenerated claw showed any tendency to revert to the larval type, 
