156 



THE MICROSCOPE. 



Oct. 



when examined in this manner. When properly done, the ef- 

 fect is equal to a spot lens or a parabaloid. 



CORRES^^JSIDENCE. 



Dr. Shufeldt's Improvised Apparatus for Making Micro- 

 Photographs of the Parasites of Birds. — Every one of us 

 who have collected birds have often noticed that if the speci- 

 mens are set aside for a few hours, and the bodies become cold, 

 numerous little parasites which have infested them during life 

 now crawd out upon the ends of the feathers or bristles around 

 the base of the mandibles. Here they will often remain until 

 they starve to death and fall off, or disappear in other Avays. 



Hundreds of times I have looked at them with a high-power 

 hand-lens with great interest, but never made any sketches of 

 them, as I had at that time devised no means to do so with ac- 

 curac}'. Later, I was again attracted to the subject, but owned 

 no micro-photographing instrument of any kind. But a day 

 or so ago I determined to overcome this most serious difficulty 

 and improvise a micro-photographing apparatus of some form 

 or other, and in the venture I succeeded far beyond my most 

 sanguine expectations. 



This is the way I did it, and my sketch of the affair as finally 



