SENSE ORGANS. 



45. Stimulus of sound : a leg joint of an orthopteran insect seen under the low 

 power to show the membrane of the ear. 



46. Stimulus of light : the eye of an albino rabbit arranged to show the 

 inverted image on the retina. When the curved surface of the cornea is changed to a 

 flat surface, by placing a microscope slide in front of the eye and filling the space between 

 slide and cornea with water, the image on the retina vanishes. The image is caused to 

 reappear by placing a suitable lens in front of the microscope slide. 



