EGGIiAYING OF AGLAIS URTIC;E AND VANESSA 10. 177 



plant, and I noted four other cases in which nettle-plants, growing 

 separate, were chosen. Once I found three clusters of A. urticae ova 

 underneath a single leaf, which ova I had not seen laid, and there was a 

 fourth cluster higher up on the same plant, which had evidently grown 

 very much since the deposition of the first three batches of eggs ; the 

 leaf with the three clusters of ova was nearly at the base of the 

 plant, and was twisted and deformed in growth by the resistance 

 •offered b}' the well-glued batches of ova to the spread of the leaf 

 tissues. Two of the egg clusters had been torn asunder by the 

 growth of the leaf. The ova of A. urticae were laid in a raised 

 heap, compact and roundish ; those of 1 . /" spread over a greater 

 surface in an also very compact but "Hatter" batch. The ova 

 ■of r. in were often twice or three times as numerous as those of A. 

 urticae, an apparently full cluster took nearly two and a half hours to 

 lay, while I have only once seen an A. itrtirae laying longer than three- 

 quarters of an hour ; then the specimen was a ? of unusual size. 

 This 2 laid an exceptionally large batch of ova, which was as " wide- 

 spread," as one of I', io, and the time of laying was over an hour and 

 & quarter. The size of the ova appears to be the same in both A. 

 urticae and T'. io : their number in one cluster is evidently proportion- 

 ate to the size of the females, so also would appear to be the duration 

 •of laying. The females of both species do not always appear to lay 

 their ova all at one time, A. urticae J s occasionally laying only 

 part of their ova on one leaf, while V. io $ s, even if actually disturbed, 

 will try to return to their ova and continue laying on the same leaf. 



So far, I have seen the ova of A. urticae in all shades of green, 

 from bluish-white to almost yellow. They keep their colour very well 

 from the moment of egglaying till a day or two before the emergence 

 of the larvae, when they turn grey. Bluish-white and yellowish-green 

 ova were found in one batch — the larvae from them were normal. I have 

 only seen the ova of V. in in bluish-white to blue-green, although they 

 have also been reported to be yellow in colour (olive-green). The ova of 

 V. io are easy to mistake for those of A. urticae unless magnified, 

 when their most apparent differences are shown, consisting in a 

 smoother surface, and in that the ridges of transparent cells are not so 

 much raised as in ova of A. urticae. 1 have found the ridges to vary in 

 number from seven to nine in V. io ova (all found in a single brood) and 

 eight to ten in A. urticae ova, the number ten appearing only in one 

 brood of the sixteeen, together with the numbers eight and nine. 



While ovipositing the females of I', in seem often to be disturbed by 

 females of A. urticae when such fly near. The first time I saw a ? 

 V. io ovipositing, the insect had been laying for about an hour, a J 

 A. urticae then suddenly appeared, flying searchingly above the nettles, 

 and at once swooped down upon the V. io ? , causing the latter to fly 

 •off, while the A. urticae settled at once in the exact position of the 

 V. io ? and commenced laying a cluster of ova beside that of 1" io. 

 The V. to $ was chased and courted for a few minutes by a V. io $ , 

 the two behaving much like cock and hen sparrows. Then the S 

 flew off and the $ flew straight back to the leaf where it had laid its 

 ■eggs. It found the A. urticae J in possession and fluttered round in a 

 disturbed way. The A. urticae 2 only jerked its head a few times, 

 otherwise it would not move, and, after the two had warily tapped 

 antennae together from opposite sides of the leaf, the to gave way to the 



