WELCKER, ON MICROSCOPIC DIAGNOSIS. 



I. Observation by direct light. 



Object. 



(a) Convex, opaque; e.g. 

 opaque, erect papillae 



(b) Convex, transparent; 



e.g. a starch-gra- 

 nule 



(c) Hollow on an opaque 



object 



(d) Hollowona transpa- 

 rent object 



Simple Microscope. 



Shadow on the sideturned 



from the light 

 Dark on the side turned 



towards the light 



Shadowonthe sideturned 

 towards the light 



Dark on the side turned 

 from the light 



Compound Microscope. 



Shadowonthe sideturned 

 towards the light. 



Dark on the side turned 

 from the light. 



Shadowonthe sideturned 



from the light. 

 Dark on the side turned 



towards the light. 



II. Observation by transmitted light. 



Object. 



(a) Convex, transparent 



(b) Depressed, transpa- 

 rent 



Simple Microscope. 



Dark on the side turned 

 towards the light 



Dark on the side turned 

 from the light 



Compound Microscope. 



Dark on the side turned 



from the light. 

 Dark on the side turned 



towards the light. 



