April, 1907.] 73 



Rade d'Hyeres. In July and August rain is very rare anywhere 

 down here As a rule we get a heavy storm at the end of August, 

 but this year no rain fell between July 0th and October llth, except 

 a slight shower about September 20th." 



The weather seems to be a negligeable factor. When the moth 

 emerges, high summer reigns in both localities The storms of the 

 end of August, breaking up the long summer drought, do not appre- 

 ciably differ at tlie two localities ; they may, however, make the dark 

 stems of shrubs, &c., in the Maurettes temporarily darker. So far as 

 climate goes, then, it is always a little cooler at La Plage, this should 

 make La Plage specimens darker ; there is more rain at Hyeres, but 

 this does not affect the period when the moth is out ; I wondered if 

 the August storm made the later emergences darker. I think the few 

 earlier emergences are generally pale. 



A census of 48 consecutive dark specimens showed that 54 pale 

 ones emerged against the first 24, and. 71 against the second, so that 

 here the results are the other way. The moths emerge at all hours, 

 but the mass about 6 — 8 p.m. ; there is a second maximum about 

 8 a.m. I tabulated these for a time and found that the morning 

 emergence showed 34 light to 9 dark, the evening 92 light to 39 dark ; 

 the difference is considerable, but I do not see what conclusion we 

 can derive from it. 



Taking note of Mr. Powell's report that the weather at Hyeres 

 usually remains fine and dry during August, but is usually broken by 

 a thunderstorm about the end of the month, I have tabulated all the 

 emergences of liycrana from the Maurettes, with a view to learn if 

 there is any tendency for the darker moths to be more frequent later 

 in the season. It must of course be remembered that these dates 

 refer to moths at Reigate, not at Hyeres. The figures are — 



PALE. 



54 63 



Taking the tabulation in another way, it appeared that of each 

 form half had emerged at dates as below : — 



Pale... [ | -^^'P*^- 22- j gept. 19. Daek... [ \ ;;;S'^P^- J^;;; ] Sept. 18. 



G 



