G. H. F. Nuttall 
397 
Record relating to the development of a male and female Phthirus from 
the egg to the adult stage, and ending with their death. 
1917 Male (see Fig. 7) 
1. Emerged as Lsi .stage larva before 8.,30 
a.m. Placed at base of single hair at 
10.30 a.m. and started to feed at once. 
2. Had not moved, body swelling. 
5. ,, ,, ajipeared somewhat 
shrivelled. 
6. Moulted to 2nd stage larva, shifted 15 
mm. Now and henceforth grasping 
two hairs with its hind leg-pair. 
7. Shifted 45 mm. 
8. Had not moved. 
9. Shifted 14 mm. 
10. Moulted to 3rd stage larva, shifted 4 mm., 
wandering. 
11. Shifted 9 mm. 
12. „ 5„ 
13. „ 6 „ 
14. Moulted to adrdt, shifted 9 mm. 
15. Had not moved at 8 a.m., but by 11.30 
a.m. had shifted 50 mm. up leg. Ap¬ 
pears well fed, body dark, ca. 1-2 mm. 
long, claws of hind leg-pair 2 mm. 
apart. 
16. Had not moved. 
17. Shifted 100 mm., wandering down leg on I 
stocking, transferred up to near $ B. ! 
18. 
Had not moved. 
19. 
Shifted 34 
mm. Copulated 19-20th day? 
with 5 B. 
20. 
„ 51 
21. 
„ 8 
,, [1st fertile egg laid by 
?B.] 
22. 
,, 15 
,, [1st egg laid by ^ D is 
infertile.] 
23. 
„ 26 
>> 
24. 
„ 40 
,, Found wandering, put 
near $ D. Sides of 
male’s body greenish 
25. 
„ 9 
26. 
„ 8 
„ Beneath 5 D. copulated ? 
27. 
„ 29 
> > 
28. 
29. 
” 'I35 
” J 
,, Copulated with $ B. 
.30. 
5 
J? 
31. 
„ 10 
») 
32. 
„ 3 
33. 
» 4 
i9 
34. 
Had not moved. 
35. 
,, Found dead; had Lived 
22 days as adult. 
Female (see Fig. 8) 
7 . V, 1917 
Tlay 
1. Emerged as ls< stage larva at 11 a.m. 
5 p.m., anchored on one hair and fed 
at once. 
2. Had not moved, body swelling. 
6. Moulted to 2nd stage larva, sliifted 
29 mm. 
7. Had not moved. 
9. Shifted 20 mm. 
10. Had not moved. 
11 . 
12. Moulted to 3rd stage larva, shifted 11 mm. 
13. Shifted 3 ram., body flat, ca. 0-75 mm. 
long. 
14. Had not moved. 
17. Moulted to adult, shifted 40 mm., ca. 
1-5 mm. long. 
No. of eggs laid 
18. 
Shifted 10 mm. 
0 
19. 
„ 10 „ 
1 
20. 
„ 40 „ 
2 
21. 
!) 3 ,, 
1 
22. 
„ 20 „ 
2 
23. 
., 33 
„ 3 
24. 
„ 59 
9 
25. 
„ 13 
3 
26. 
„ 53 
9 
27. 
„ 89 
„ 3 
Sides of $ B’s 
body greenish. 
28. 
„ 22 
9 
29. 
,, 15 
„ 1 
30. 
„ 17 
9 
31. 
Had not moved 2 
32. 
„ _o 
33. 
Found dead; had 26 
Total eggs laid 
lived 1 
17 days 
by$B. 
as adult 
N.B. The movements having been recorded but once in 24 hours, the chart naturally 
does not represent all the changes of position that took place. When it is stated that the 
insect “shifted” a certain distance, the measurement is given arbitrarily in a straight line 
from the last point of attachment to the new, irrespective of the wandering that took 
place from point to point. That such meanderings took place is evident from the female’s 
chart, wherein the position of the eggs laid on hairs in a hypothetical order is denoted 
by clear circles as opposed to black spots denoting anchorages. (See charts, next page.) 
