THE MICROSCOPE. 



and run almost up to the gustatory pore. They end by means 

 of minute swellings which lie on the gustatory cells. The 

 intergemmal fibres which end between the taste buds do not 

 differ in their termination from other free nerve-endings in 

 stratified pavement epithelium. Their dendritic end branches 

 run to the most superficial layers of corneous epithelium, 

 where they terminate in fine end bulbs. 



GENERAL MICROSCOPIC TECHNIQUE. 



1. THE MICROSCOPE. 



Although it is impossible here to enter into a detailed dis- 

 cussion of the theory of the microscope, it is nevertheless 

 necessary to give an outline of its main parts. Two kinds of 

 microscopes may be spoken of: the simple microscope, which 

 contains only simple lenses, and the compound microscope, in 

 which there are many lens systems. The latter instrument is 

 much more powerful than the former. It consists of two parts, 

 the stand and the lenses. 



The stand consists of an upright column which rests on 

 a wide base. Fastened to this is a hollow cylinder, in 

 which fits the tube which contains the lenses. There is also a 

 platform or stage for the object examined, and a mirror. The 

 stage, which is situated between the tube and the mirror, has at 

 the point opposite the end of the tube a round hole through 

 which the light rays are reflected from the mirror to the object. 

 The intensity of this light is regulated by a diaphragm, which 

 is placed under the opening in the stage. This may be the 

 so-called iris diaphragm, which can be controlled by the hand, 

 so that the opening may be made any size that is wished. The 

 mirror usually possesses a flat surface on one side, which is 

 used with low magnifications ; and a concave surface on the 

 other side, to be used when higher magnifications are employed. 

 With the concave mirror the light rays are converged on the 

 object. In order to concentrate the light rays still more, the 



