Mr. Rennie on the Cleanliness of Animals. 



17 



caudal instrument I discovered, by this means, to consist of a 

 double row of white cartilaginous rays, disposed in a circle, one 

 row within the other ; and, what was most singular, these were 

 retractile, in a similar manner to the horns of the snail. The 

 rays were united by a soft, moist, gelatinous membrane, but so 

 as to be individually extensile ; one or two being frequently 

 stretched beyond the line of the others. The rays were also 

 capable of being bent as well as extended, and they could 

 therefore be applied to the angles or depressions of an uneven 

 surface. 



It was not long before I convinced myself that this singular 

 instrument was employed by the insect for cleaning itself ; and 

 it would have been difficult to devise anything more effectual 

 for the purpose, though its action was different from all others 

 of this kind with which I was acquainted, inasmuch as it 

 operated by suction, and not as a comb, a brush, or a wiper, 

 of which I shall mention some examples in the sequel. It 

 was, moreover, furnished in the interior with a sort of pocket, 

 of a funnel shape, formed by the converging rays, into which 

 was collected whatever dust or other impurities were detached 

 from the body, till it could hold no more, when, by a vermi- 

 cular movement of the rays, the accumulated pellet was ex- 

 truded, and placed with great care in some place where it 

 might be out of the way of again soiling the glossy skin of the 

 insect. This skin, if I may call it so, was of a soft, leathery 

 appearance; exhibiting, when magnified, a minute delicate 

 dotting, similar to shagreen but to the naked eye this was 

 not apparent. 



a 



a 



Magnified views of the cleaning Instrument, open and closed, a, the under side of the body j 

 b t the cleaning instrument. 



VOL, I. 



OCT. 1830. 



