1914.] 29 



Pezold observed and describes and figures the fans of the eighth 

 abdominal segment. He says they were extended and withdrawn 

 without intermission when the larvae were feeding. He saw no fluid 

 or other secretion from them, but was able to detect a scent. He 

 failed to notice the honey-gland, but seemed strongly of opinion there 

 was some honey, apparently regarding the fans as closely analogous to 

 the honey-cornicles of Aphides. His final remark is very noteworthy : 

 he says, may it not be that the ants, which in the case of the Aphides 

 give such assiduous attention for the sake of the humour they exude, 

 find in this case also some similar exudation ? that he could detect no 

 such secretion, by no means proved that there was none, and hopes 

 that time may permit him to learn more about it. 



It is not impossible that he later discovered all about the honey- 

 gland, but if he did, no record of the circumstance is known. 



EXPLANATION OF PLATES I— VII. 



Plate I. Figs. 1-9. Coloured figures of the larvae of A. damon and 

 P. argyrognomon. 



Plate II. Fig. 10. Skin of larva of P. argyrognomon in first stage, spread 

 out showing hairs, lenticles, etc., X 67. 



Plate III. Fig. 11. Skin of larva of P. argus {segon) in first stage, simi- 

 larly treated, for comparison with fig. 10. X 67. 



Plate IV. Fig. 12. Skin of prothoracic dorsum of larva of A. damon in 

 last stage, X 30; fig. 13, dorsum of 7th-10th abdominal segments of A. damon, 

 X30. 



Plate V. Figs. 14, 15. Honey-gland region of larva of A. damon in last 

 stage, X 114 ; fig. 14, superficially focussed, showing hair-bases and lenticles 

 crowded round the gland ; fig. 15, focussed more deeply, showing the four 

 circles on floor of gland. 



Plate VI. Fig. 16. Prothorax of last stage larva of P. argyrognomon, X 30 ; 

 fig. 17, dorsum of 7th-10th abdominal segments of same larva. 



Plate VII. Fig. 18. Honey-gland of same specimen, X 114; fig. 19, first 

 proleg of same larva, X 114. 



Betula, Reigate : 



December, 1913. 



