510 



CILIARY MOTION. 



Fig. 208. 



This ciliary motion has been 

 seen in different animals, on the 

 external surface, in the aliment- 

 ary canal, the respiratory sys- 

 tem, the female generative or- 



gans ; 



and in the cavities of the 



Cilia. 



nervous system. It has not been 

 observed, however, in the vagina ; 

 but may be traced from the lips 

 of the os uteri through its cavity, 

 and through the Fallopian tubes 

 to their fimbriated extremities. 

 In the upper classes of animals, 

 it is not witnessed on the external 



1. Portion of a bar of the gill of the Mytilis edu- Q 1ir .fq/>p pvnpnt in thp pmhrvn Tn 



If*, showing cilia at rest and in motion. 2. Ciliated SUHdCC CXCCpt in tE DryO. ^ 



epithelium particles from frog's mouth. 3. Ciliated most animals, a high magnifying 

 epithelium particle from inner surface of human . 3 . * . 



membrana tympani. 4. Ditto, ditto : from the human pOWCr IS nCCCSSary to perCClVC it. 

 bronchial mucous membrane. 5. Leucophrys patula, A email r^io^o rf Tniinmia TYIPTYI 



a polygastric infusory animalcule; to show its sur- A Small plCCC 01 HlUtOUS mem- 



face covered with cilia, and the mouth surrounded by b rane on W hich it exists, should 

 them. (Todd and Bowman.) ' . 



be moistened with water, and 



Fig. 209. covered with a plate of glass, by 



which the membrane is spread 

 out, and its border rendered clear- 

 ly visible. With the aid of a pow- 

 erful microscope, an appearance 

 of undulation is perceptible, and 

 small bodies floating in the water 



Vibratile or Ciliated Epithelium. , ~ t, j c 



may be seen, near the border or 

 mftie* u ttina c . ells ' *** on their smaller **** the membrane, to be driven along 



in a determinate direction. With 



a still higher magnifying power, the cilia themselves may sometimes 

 be recognized, although seldom very distinctly, owing to the great 

 rapidity of their motion. The influence of the motion on the fluids 

 and small bodies in contact with the membrane may be well exhibited 

 by strewing a fine powder on the surface ; as the motion of the cilia 

 has a uniform direction, it gives rise to currents over the surface of the 

 membrane. 



An easy mode of observing the phenomenon is to scrape with a 

 knife a few scales of epithelium from the back of the throat of a living 

 frog. If these be moistened with water or serum,* they will continue 

 to exhibit the motion of the adherent cilia for a very considerable time, 

 if the epithelium be only kept moistened. On one occasion, Messrs. 

 Todd and Bowman observed a piece of epithelium prepared in this 

 manner exhibit motion for seventeen hours ; and they thought it would 

 probably have done so for a longer time had not the moisture around 

 it evaporated. In the turtle, after death by. decapitation, MM. 

 Purkinje and Valentin found it lasted in the mouth nine days; in the 

 trachea and lung, thirteen days; and in the oesophagus, nineteen days. 1 



1 Physiological Anatomy and Physiology of Man, by Messrs. Todd and Bowman, p. 62, 

 Lond., 1843. 



