46 PRACTICAL MICROSCOPY. 



this beard, add a drop of the liquid from the oyster, and tease with a 

 pair of needles. Apply the cover and focus H. 



At first, the individual cilia cannot be demonstrated on account of 



Fio. 29. CILIATED COLUMNAR CELLS FROM BRONCHUS OF PIG. X 400. 



their rapid vibration. After a few moments, however, the action be- 

 comes less energetic, and the hair-like appendages of the cells are to 

 be plainly seen. 



FIG. 30. OYSTER, OPENED TO SHOW METHOD OF PROCURING LIVING CILIATED CELLS. 



A. The divided muscle. This must be sectioned before the shell can be opened. 



B. The Heart. 



C. Liver. 



D. D. The so-called " beard." These laminae are covered with cells provided with cilia ; and 

 a fragment of the free border of one of the leaflets may be snipped with the scissors, and 

 examined as described in the text. 



Of course none of the above objects are intended to be perma- 

 nent. 



