74 THE MICROSCOPE. 



will only require a few minutes, the slide should be 'flooded' with 

 stain A. 



This should be allowed to remain on for about three minutes, 

 at the end of which time, it may be washed by gently waving back 

 and forth in a glass of clean water. Before it is allowed to dry, the 

 corpuscles should again be flooded, this time with stain B. After 

 two minutes exposure to this fluid, the slide should be washed, as 

 before and set away to dry. When dry, a drop of Canada balsam 

 may be put upon the blood, a cover-glass applied and the whole 

 gently warmed until the balsam spreads out properly. When hard 

 it may be finished the same as is usual with balsam mounts. 



Tf now examined with the microscope, the corpuscles will be 

 found to be well stained with red, while the nuclei and "leucocytes" 

 will be a blueish-green. 



The granular appearance which is ordinarily seen in the nuclei, 

 now shows with a vigor and sharpness which is difficult of descrip- 

 tion, while the whole corpuscle is as brilliant as a newly cut ruby. 



In regard to the structure of the corpuscles, I can say but little. 

 I have never had any difficulty whatever in seeing a distinct granu- 

 lar appearance in the nucleus, provided a first-class objective was 

 used. But so far as a network is concerned, I have completely 

 failed to see anything that could be called such, except when the 

 objective used was improperly adjusted for thickness of cover or 

 immersion fluid. In such cases the dots or granules "appear to run 

 into lines," and a reticular structure may be interpreted. Even by 

 the use of boracic acid I have completely failed to "bring out" the 

 network. 



It has been held by some that the corpuscles are covered by, 

 or enclosed within, a " limiting membrane," but those who have 

 endeavored to substantiate their claims — upon either side of the 

 question — have failed as yet. 



Figs. I, 2, 3, 4, 5 and 7, of the plate, show the general character 

 of the double stained corpuscles. Fig. 6 is a red corpuscle from 

 the blood of the snapping turtle, and shows the granular nature of 

 the nucleus very well. The granules in the nuclei of these seem to 

 be larger in proportion to the corpuscles than in any other with 

 which I am acquainted. Fig. 9 is a corpuscle from the newt. This 

 corpuscle also shows the granular nucleus nicely; but the most 

 remarkable thing is the peculiar way in which the corpuscle is 



