GENERAL PHYSIOLOGY. 19 



and examine with a microscope. If the preparation 

 has been properly made the margin of the tissue 

 should, at certain points, show the cause for the 

 phenomena above observed. Study the character 

 of the ciliary movements. Describe. 

 (4) Study ciliary movement with higher power. It is 

 probable that the first preparation is not suited to 

 observation with a high power. If the cilia cannot 

 be readily brought into focus, prepare a second one 

 as follows: From the ciliated surface clam-gill 

 or frog oesophagus scrape a few epithelial cells, 

 with the point of a scalpel, place the minute bit of 

 tissue upon a cover glass; add a small drop of saline 

 solution; gently tease the tissue with needles, in- 

 vert the cover upon a slide, allowing one edge to 

 rest upon a hair, to avoid undue pressure upon the 

 tissue. 



Focus under high power (300-600 diam.). If the 

 preparation is successful groups of ciliated cells 

 may be seen and the character of the ciliary move- 

 ment studied. 



b. Ciliary motion modified by the influence of nar= 

 cotics and stimulants. 



1. Appliances. In addition to the appliances enumerated 



above under a, one needs : A gas flask and siphon as 

 shown in Fig. 1. Also a cell slide with conducting 

 tube. (Fig. IB.) A gas generator will be necessary 

 unless there is a large generator for general use by 

 the class. HC1 25%, marble, chloroform, ether, ab- 

 solute alcohol, sealing wax, thread, small glass tube, 

 soft parafin. 



2. Preparation. To prepare a cell slide with conductor. 



(1) From a hard rubber ring, having an inside dia- 

 meter of about 1 cm, and a thickness of about 



