26 ' [February, 



the moth appears at the beginning of July." Eagonot's further 

 remarks [Eom. Mem., vii, 199 (1893)] on this difficult problem seem 

 worth quoting, and are as follows : " The late von Horning wrote to 

 me that he had collected cones of Abies r)edinata in Bohemia in 

 November, and the moth emerged in March (no doubt in a heated 

 room). He also collected the cones of Abies nigricans and excelsa in 

 July and obtained the moths in September, which were like the others, 

 but smaller and paler ; he concluded that there were two broods, but 

 it is probable that there is only one, the more advanced larvse 

 producing the moths in September (confirmed by Mons. Lafaury), the 

 others hibernating. No one seems to have observed in the autumn 

 the larva that lives in the shoots of the pines, nor sought for the 

 differences which may exist between the moths of the larvse inhabiting 

 the cones, and those living in the stems ; I am therefore obliged to 

 consider these two laiwse, which are in other respects very similar, as 

 constituting one and the same species." 



Since Eagonot's words were penned, though without any laiow- 

 ledge of them, I have carefully sought for differences in the moths 

 from the larvse inhabiting the cones and from those living in the 

 shoot- stems, but in vain. The idea of the insect being truly double- 

 brooded in Britain seems to me untenable, nor are any facts known to 

 me that suggest that, with us, the more advanced larvse ever produce 

 imagines in the autumn. One remarkable fact, however, is worthy of 

 record. On December 2nd, 1904, Mr. A. Thurnall found, in a cage in 

 which he had placed a few tenanted Scotch pine cones, received in 

 October from near Bournemouth from Major Eobertson, a true cocoon 

 containing a pupa, which he had no doubt was referable to abietella, 

 but when the pupa was examined in the following August, it had 

 evidently been dead for a long time. 



Some of the larvse feeding in the cones are barely half-grown 

 by the late autumn, and obviously cannot feed up before the fol- 

 lowing year : in confinement, these leave the cones during November, 

 and wander about until they die, nor did Major Eobertson succeed in 

 inducing them to setttle down on shoots of Scotch pine. In spite of 

 his want of success, however, a review of all the facts at hand makes 

 me think it probable that, in Britain, all the eggs are laid during the 

 summer on green cones of P. sylvesfris, that the larvse from the earlier 

 eggs become full-fed about October, when they leave the cones to spin 

 hibernacula on the ground, finally pupating in true cocoons thereon in 

 the spring, while those from the later eggs, being still immature. 



