440 MANIPULATION. 



Stomach and intestines, and even the lungs; each prism is 

 attached end-ways to the basement membrane, and is united 

 to its fellows by the sides, so that they form a single layer, 

 the thickness of which depends upon the length of each prism; 

 the attached extremity is generally pointed, the free one wide 

 and flat ; this latter, in some parts, is provided with vibratile 

 cilia; the best situation for the examination of these is the 

 villous surface of the small intestine of animals ; if the ciliary 

 movement is desired to be viewed, the upper and back part of 

 the Schneiderian membrane, or some portion of the respira- 

 tory tract, may be selected, as in these spots the prisms are 

 clothed with cilia, and may be observed in rapid movement 

 some little time even after the death of the animal. The third 

 variety, or spheroidal, is to be met with in all glandular 

 structures ; and so constant is its presence in them, that the 

 name of glandular has often been appUed to it. The parts in 

 which it may be readily examined are the tubes of the stomach 

 and kidney ; the secreting structure of the liver is also made 

 up of it. In the two former situations, the basement mem- 

 brane, upon which the epithehum rests, can be very well seen ; 

 but in the liver, where the cells are most abundant, it cannot 

 be detected. 



The movement of the cUia was known to the old microsco- 

 pists, even as far back as the days of Leeuwenhoek, and from 

 that time up to the present has always been viewed with 

 wonder and amazement; it was first discovered in the 

 infusoria, and afterwards in some of the small molluscous 

 animals ; in more modern times it has been detected in all the 

 higher classes, up to man himself. Those who would wish to 

 obtain accurate information upon the subject of cUia, should 

 consult the articles " Cilia" and " Mucous Membrane," in the 

 CyclopcBdia of Anatomy and Physiology. 



Method of Viewing the Ciliary Movement. — If the roof of the 

 mouth of a living frog be scraped with the end of a scalpel, 

 and the detached mucous matter placed on a glass slide, and 

 examined with a power of two hundred diameters, the ciliated 

 epithelium cells may be well seen ; when a number of these 

 are collected together, the movement is effected with apparent 



