102 



an undeveloped imago state^ — the latter being either 

 entirely apterous or with the fore- wings rudimental, 

 although occasionally to be met Tvith having the fore- 

 wings completely developed*." The common Phos- 

 phuga atrata of our own country has the organs of flight 

 very rudimentary, and much too small for use : yet the 

 late Mr. Holme of Oxford has mentionedf, that he has 

 several times taken it on the wing, during the hot sim- 

 shine. And, concerning the Olisthopus rotundatus, he 

 states f that every specimen which he captured in the 

 ScUly Islands was subapterous. 



But facts like these are, after all, nothing more than 

 such as we may trace the counterpart of in higher ani- 

 mals than the Insecta. Mr. Gould informs me, that the 

 Swallows of Malta, which have but a comparatively 

 narrow space to cross over, to the African continent, 

 constitute (although specifically identical with them) a 

 distinct race from those of England, — all of which, he 

 believes, winter in Morocco. But, what are the differ- 

 ences displayed? From amongst many minor ones, of 

 a climatal or geographical natiu'e, the most conspicuous 

 is the length of the wings, — those which have annually a 

 longer journey to perform having, through a course of 

 ages, acquired, as a race, a superior capacity for flight. 

 And, in answer to a late query on this subject, he adds 

 that all the sylvan birds in Malta, such as the Black- 

 caps, WiUow-wrens, &c., though imquestionably of the 



* Introduction to the Modern Classification of Insects, ii. p. 473. 

 t Trans, of the Ent. Soe. of London, ii. p. 60. J Id. ii. p. 69. 



