A very large number of Gynandrous, or "hermaphrodite" specimens have been recorded, several of them from Britain; in most of these the gynandromorphism is bilateral, that is the insect is wholly male on one side, and entirely female on the other. In some the right side is male, in others the left side; the opposite side in each case being female. Much information on this subject and on Hybridism of the Sphingidæ will be found in Tutt's "British Lepidoptera," vol. iii.
The pale shining green eggs are laid, generally singly, but sometimes in twos, threes, or more, on either surface of a leaf of poplar or sallow. Now and then batches of eggs may be found, and these have probably been laid by females that were crippled on emergence, or had been afterwards injured in some way and so were unable to fly.
| Pl. 4. |
| Poplar Hawk-moth. |
| Eggs, natural size and enlarged; caterpillar and chrysalis. |
| Pl. 5. |
| Poplar Hawk-moth. |
Fig. 17.
Eggs of Poplar Hawk-moth.