THE MICROSCOPE. 



J AXU ARY, 



1893. 



Number i. (New Series.) 



INTERPRETATION OF APPEARANCES UNDER THE 



MICROSCOPE. 



By Prof. S. H. Gage, 



ITHACA, N. Y. 



[From Microscope and Histology, pp. 29-31.] 



It is important to remember that the more of the relations of 

 any object are known, the truer is the comprehension of the object. 

 In microscopical investigation every object should be scrutinized 

 from all sides and under all conditions in which it is likely to oc- 

 cur in nature and in microscopical investigation. It is best also 

 to begin with objects of considerable size whose character is well 

 known, to look at them carefully with the unaided eye so as to see 

 them as wholes and in their natural setting. Then a low power 

 is used, and so on step by step until the highest power available 

 has been employed. One will in this way see less and less of the 

 object as a whole, but every increase in magnification will give 

 increased prominence to detail, detail which might be meaning- 

 less when taken alone and independent of the object as a" whole. 

 The pertinence of this advice will be appreciated when the 

 student undertakes to solve the problems of histology ; for, even 

 after all the years of incessant labor spent in trying to make out 

 the structure of man and the lower animals, many details are 

 still in doubt, the same visual appearances being quite differently 

 interpreted by eminent observers. 



Dust or Cloudiness on the Ocular. — Employ the iS mm. 

 (f in.) objective, low ocular, and flv's wing as object. 



Unscrew the field-lens and put some particles of lint or dark 

 cloth on its upper surface. Replace the field-lens and put the 

 ocular in position. Light the field well and focus sharply. The 

 image will be clear, but part of the field will be obscured by 

 the*irregular outline of the particles of lint. Move the object to 

 make sure this appearance is not due to it. 



Grasp the ocular by the milled ring, just above the tube of the 

 microscope, and rotate it. The irregular object will rotate with 



