EXPERIMENTS ON FLIES. 395 



perhaps the expression thrown into the grey eye by this tinge of black, 

 contributes more towards that beauty of countenance to which he 

 alludes, than any imagined mixture of Goths and Celts : for, whatever 

 inferiority the dark complexion may labour iinder, with respect to the 

 hue of skin, yet it must be allowed, that it communicates a certain 

 degree of expression to the countenance, which the fair sanguine 

 temperament never can possess. And, though the claims of the fair 

 complexion to mere beauty cannot be disputed, yet it almost entirely 

 depends upon its protection from the sun and weather; for when the 

 sanguine complexion loses its fair hue by exposure, the fine expression 

 of the blue eye is completely lost : "and in men, when the face is much 

 tanned by the sun, there is a certain species of light blue eye, which 

 assumes an aspect often exceedingly sinister and unpleasant, so as 

 perfectly to explain the classic expression of truces oculi : but the 

 dark complexion bears the influence of the sun much better, and strong 

 manly features are generally even improved by its bronzing effects. 



MR. BLACKWALL'S EXPERIMENTS ON FLIES*. 



THE various papers we are sorry to say short papers which Mr. 

 Blackwall has occasionally contributed to Natural History, are charac- 

 terised by much originality, and at the same time have little of the 

 speculative fancies that so frequently vitiate the researches of our most 

 ingenious observers. The account given by Sir E. Home of the struc- 

 ture of the foot in flies, enabling them to walk on smooth glass against 

 gravity, was considered so satisfactory, that it has been adopted by 

 most succeeding writers. This account Mr. Blackwall, however, found 

 to disagree with his own observations, as well as to be at variance with 

 those of Hooke and Derham, and determined to examine the subject 

 with care and minuteness. 



" Satisfied," says Mr. Blackwall, " that this difficult problem must admit of 

 a solution more consistent with the various phenomena it comprehends, than the 

 popular one here controverted, I determined to institute an experimental inves- 

 tigation of it. Accordingly, having procured living specimens of the house-fly 

 (Musca domestica), and of the large flesh-fly (Musca yomitoria), I enclosed them 



* Remarks on the Pulvilli of Insects. By John Blackwall, Esq. F. L. S. 

 Linn. Trans, vol. xvi. 



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