(x. H. F. Nuttall 
137 
Expt. 3'. The $$, after 5 days, had laid 114 eggs on hair and 10 on 
cloth. 
The total for the three experiments was 157 eggs laid on hair and 
14 laid on cloth or felt. This result strongly bears out Bacot’s con¬ 
tention that capitis shows a very marked preference for laying on hair. 
(c) Does corporis attach her eggs to hair in a different manner to 
capitis? The statement by Bacot (26. n. 1917, pp. 231-232) that 
corporis lays its eggs on hair less skilfully than capitis is contrary to my 
experience during the last two years; I had failed to notice any differ¬ 
ence of the kind in hundreds of eggs laid on hair. From what has 
been said of the function of the gonopods which serve to bring the egg 
into alignment upon a hair, it seemed to me incredible that there 
should be such a difference. I had also failed to observe any greater 
tendency in corporis than capitis to oviposit on two or more hairs at 
once or at the intersection of hairs, and therefore concluded, on reading 
Bacot’s paper, that he was misled by a subjective impression. To 
exclude this source of error some counts were made of eggs laid on hair, 
the result being as follows: 
(1) Regarding the alignment of the eggs on hairs: (a) Some hairs 
bearing eggs of corporis, dating from older experiments, were reexamined. 
The females had laid the eggs on fine ladies’ hair placed in small quan¬ 
tity, haphazard in a tube containing the insects. Out of a total of 
79 eggs, only 4 were not in perfect alignment and one of these was 
misplaced through contact with a previously laid egg. (b) In Expts. 
3, 3', previously described as conducted on hair-frames, corporis laid 
86 eggs of which 2 were out of alignment; and capitis laid 114 on hairs 
of which 2 were out of alignment, (c) In another case, corporis laid 
61 eggs, 9 thereof being out of alignment. 
The slight differences observed would appear at first sight to support 
Bacot’s view, but closer inspection showed that eggs laid out of align¬ 
ment were usually placed alongside of others that had been laid pre¬ 
viously. Out of 11 corporis eggs out of alignment only one was not in 
contact with other eggs; of 2 capitis eggs one was in such contact 
and one isolated. When an egg is laid in contact with others whose 
cement has hardened, it may well be misplaced to one side without 
this being due to any fault of the insect. In the experiment with 
capitis, the eggs were laid somewhat further apart than with corporis, 
which circumstance also explains why fewer were out of alignment. 
A subsequent examination of 47 6 capitis and 356 corporis eggs, laid on hair- 
grids, gave concordant results, and it was again noticed that corporis laid its 
