Ciliary Motions in Reptiles and Warm-blooded Annuals. 125 



not to be understood in the sense in which it has occasionally 

 been employed of late, as, for example, when applied to a pecu- 

 liar appearance in the blood. On the contrary, we use it to de- 

 note a phenomenon as well defined and regular as any in nature* 

 It no doubt sounds strange that hairs should be found on the 

 mucous membrane of the respiratory passages, or that hairs or 

 cilia should exist at all within the body, especially to such an 

 extent; but in proof of it we can confidently refer every one to 

 his own observations, which are here easily made. We must 

 frankly own, however, that, in order to form a competent judg- 

 ment, it is requisite to command a clear magnifying power of 

 from three to four hundred diameters. Whoever is provided 

 with such means, and attends to the precautions above pre- 

 scribed, will be able easily to perceive and to admire one of the 

 most beautiful phenomena in nature. 



We hope very soon to make known the entire of our obser- 

 vations on the vibratory motions in the animal kingdom gene- 

 rally, in a special work which we may perhaps be able to sub- 

 mit to the public in the beginning of next year. 

 Breslaw, 4lh July 1834. 



. Additional Observations and Experiments by Dr Sharpey. 

 Since learning of the interesting discovery of Messrs Purkinje 

 and Valentin, I have repeated several of their observations ; and, 

 as in a subject of this sort, it is important to be able to compare 

 the results obtained by different persons; I beg to subjoin a 

 statement of those I have hitherto met with ; more especially as 

 I have in some cases ascertained the direction in which the 

 propulsion of matters along the surface takes place, a circum- 

 stance not mentioned by the authors in their present preliminary 

 memoir. 



On examining one or more examples of mammalia, birds and 

 reptiles, I have been able satisfactorily to perceive the ciliary 

 motion in all the three classes. The cilia, indeed, are very mi- 

 nute, and their presence is indicated rather by the oscillatory 

 motion which they conjunctly exhibit, than by their individual 



translation ; but the term " vibration" has been before applied to the motion 

 of the cilia, and is used also by the authors themselves as synonymous with 

 the other. 



