120 Ciliary Motions in Reptiles and Warm-blooded Animals. 



inner surface, on which the vibratory motion is visible, but the 

 motion is confined to the elevation being wanting on the rest of 

 the tube, a circumstance seeming to indicate that the part in 

 question is connected with the generative function.* We have 

 as yet been equally unable to discover the phenomenon in the 

 male generative organs, the gall-bladder and ducts, the excre- 

 tory ducts of glands, the urinary passages, the cerebral and spi- 

 nal arachnoid membrane, the internal surface of the bloodvessels, 

 the surface of the blood-globules, the membranes of the ovum 

 and envelopes of the fcetus, and the skin. 



In Amphibia, such as serpents, lizards, and the like, in birds 

 and in mammiferous animals, the mucous membrane of the ovi- 

 duct exhibits the vibratory motion throughout its entire extent, 

 both in the impregnated and un impregnated state, and the 

 smallest portion, when examined with the precautions to be af- 

 terwards prescribed, is sufficient to show it. The same is the 

 case with the mucous membrane of the respiratory passages, 

 from its commencement to its termination ; in so much that the 

 presence of the property in question may serve as a sure test of 

 the system to which the parts exhibiting it belong. In the 

 mammalia the motion occurs over the whole lining membrane of 

 the windpipe and its branches, extending to the smallest divi- 

 sions which admit of investigation, but no trace of it can be 

 found in the glottis and its ligaments, nor in the lining mem- 

 brane of the mouth and pharynx. On the other hand, it is very 

 conspicuous in the nose, and it ceases abruptly in the most strik- 

 ing manner at the limit between these parts. In reptiles, such 

 as the salamander, however, in which the mouth is not merely 

 an organ of deglutition, but serves also for respiration, the mu- 

 cous membrane of the throat exhibits the motion in a very 

 lively and conspicuous manner. 



Should it be ultimately established that only the respiratory 

 and genital membrane possess this property, it would afford a 

 new fact in support of the analogy already held on many other 

 grounds to subsist between them. 



* I have, however, as already mentioned, found the motion on the inner sur- 

 face of the digestive organs of the Echinodermata, the Annelida, and Actinia, 

 and it exists in the alimentary cavity of many polypi.— W. S. 



