\C)8 Description of the Tongue and 



(2.) When clouds appear coloured, I believe that the colour 

 exhibited is for the most part not formed in the cloud itself, 

 inasmuch as the little bladders generally differ too much in 

 thickness to cause the production of a single determinate 

 colour ; but that the light, partly on its way to the cloud, and 

 partly between the cloud and our eye, assumes its colour ; 

 even in the apparently clear air there always exist bladders, 

 which, however, are for the most part so attenuated, that they 

 favour in a particular manner the formation of the first 

 colours of interference, namely blue and orange-red. — I re- 

 main, Gentlemen, very respectfully yours, 



R. Clausius. 



Berlin. Oct. 13, 1852. 



Description of the Tongue and Habits of the Aardvark 

 or Ant-eater of the Cape {Orycteropus Capensis). By 

 William T. Black, Assistant- Surgeon to the Forces, 

 South Africa. Communicated by the Author. 



In Professor Jones' General Outline of the Animal King- 

 dom, is to be found a description of the elongated tongue of 

 the Ant-eaters of South America, and the Echidna of New 

 Holland. The Aardvark (the Earth-hog, Dutch) and these 

 two animals, belong to the order of Edentata, but the last is 

 further distinguished by being monotrematous. Whether 

 Professor Jones' description is intended to refer to the 

 tongues of all the animals in that order that possess them as 

 instruments of prehension does not appear, and it may be 

 correct ; but from two or three specimens of the organ dis- 

 sected by me in the Aardvark, I am led to doubt its applica- 

 bility to this animal. Professor Jones speaks of two proper 

 muscles not found in the tongues of other mammalia, an ex- 

 ternal annular one, and an internal elongated spiral one, 

 invested by the former. These I have been unable to detect 

 in the tongue of the Cape Ant-eater, and I subjoin the fol- 

 lowing description of my acquaintance witli its lingual ana- 

 tomy : — 



