CILIAHY MOVEMENTS. 439 



in which they are to be found in the human subject. 1 

 Their presence has been demonstrated on the following 

 surfaces : The respiratory passages, including the nasal fos- 

 sae, the pituitary membrane, the summit of the larynx, the 

 bronchial tubes, the superior surface of the velum palati, 

 and the Eustachian tubes ; the sinuses about the head ; the 

 lachrymal sac and the internal surface of the eyelids ; the geni- 

 tal passages of the female, from the middle of the neck of the 

 uterus to the extremities of the Fallopian tubes ; and the ven- 

 tricles of the brain. They probably exist also at the neck of 

 the capsule of Miiller, in the cortical substance of the kid- 

 ney. In these situations, to each cell 

 of conoidal epithelium are attached 

 from six to twelve prolongations, 2 

 about ssooo of an inch in thickness' at 

 their base, and from yoW * ToVrr f 

 an inch in length. 3 The appearance 

 of the cilia in detached cells is repre- 

 sented in Fig. 15. When seen in situ, 

 they appear regularly disposed on the 

 surface, are of nearly equal length, 

 and are all slightly inclined in the 



-,. .. f . T . ,, . , Ciliated epithelium. (LOKGET, 



direction Ot the Opening OI the Cavity Tralte de physiologic, Paris, 

 ,.-,,,, 1869, tome ii., p. 579.) 



lined by the membrane. 



The ciliary motion is one of the most beautiful physio- 

 logical demonstrations that can be made with the micro- 

 scope. By scraping the roof of the mouth of a living frog, 

 the mucous membranes of the respiratory passages in a 

 warm-blooded animal just killed, the beard of the oyster or 

 clam, and placing the preparation, moistened with a little 

 serum, under a magnifying power of about two hundred and 



1 PURKINJE AND VALENTIN*, Discovery of Continual Vibratory Motions, pro- 

 duced by Cilia, as a general Phenomenon in Reptiles, Birds, and Mammiferous 

 Animals. Edinburgh New Philosophical Journal, 1835, vol. xix., p. 118, 

 et seq. 



* BECLARD, Traite elementaire dt physiologic humaine, Paris, 1859, p. 497. 



3 POUCHET, Precis d?histologie humaine, Paris, 1864, p. 189. 



