Journal of Applied Microscopy. 



objectives, where the front lens and cell 

 are exceedingly frail and the slightest 

 displacement, while it may not be 

 apparent at first, will in time almost 

 with certainty permit the leakage of oil 

 around it to the interior, and thus de- 

 stroy its utility. 



A Convenient Method for Histol- 

 ogy of Nerve Tissue. 



Henry L. Osborn, St. Paul, Minn. 



Histologists are generally of the opin- 

 ion that materials for study must be 

 perfectly fresh, and, for the best work, 

 anyone would naturally reject material 

 which was not obtained alive. In get- 

 ting material for elementary class work, 

 however, it is not absolutely necessary to 

 have perfectly fresh material, and I 

 have found that I can use a number of 

 different tissues that can be bought at 

 the butcher's shop in demonstrating the 

 coarser facts. 



After reading in Stirling's Histology, 

 page 216 (edition of 1896), the method 

 there given for showing the multipolar 

 nerve cells, I determined to give it a 

 trial on some spinal cord obtained from 

 my butcher. The beef from which I 

 took the tissue had been killed at least 

 two weeks previously, during May. The 

 cord could be seen in the spinal canal as 

 the beef was hanging in the shop, and 

 hence had been drying on the surface. 



A small particle of the gray matter 

 from the anterior root was placed on a 

 cover glass, and a second cover glass 

 placed directly on it and squeezed down 

 so as to smear the gray matter evenly 

 over both glasses. The covers were then 

 separated and floated, film downwards, 

 on a saturated solution of methylene 

 blue for two hours. Then they were 

 washed in distilled water and dried; and 

 finally, after exposure to a gentle heat 

 to thoroughly dry them, they were 

 directly mounted in balsam. 



The method is so direct and easy of 

 application that it is available for the 

 beginner. In order to test its possibili- 

 ties, I give a drawing from one of the 

 slides made by the method. I do not 

 think of any better way in which to 

 show the value of a method than to 

 show some of the work done with it. 

 The drawings were all of them made 

 with a camera lucida and are made not 

 in the least diagrammatic. Figure 1 is 

 a view of a part of one field showing 

 four nerve cells as they appeared. The 

 field included nerve fibres and deeply 

 stained small round nuclei that are not 

 introduced in the drawing; another part 

 of the field contained the arteriole and 

 its capillaries, as shown in figure 2. 



The effect for display of cell structure 

 can be gathered from figures 3, 4, and 5. 

 In figure 3 I have shown the cell in the 

 upper left-hand corner of figure 1, as 

 seen under a one-twelfth inch oil immer- 

 sion lens. The cell does not show all of 

 the points that are known to be charac- 

 teristic of the multipolar cell from this 

 situation. Thus, the method does not 

 distinguish any pigment, nor is the axis- 

 cylinder process distinguished from the 

 branched protoplasmic processes, one 

 only of which is seen to branch. But the 

 fibrillation in the protoplasm, "running 

 in different directions through the cell," 

 is beautifully shown, as well as the single 

 elements of the fibrillation, which appear 

 as very narrow and long, deeply stained 

 particles in a lighter ground, which also 

 stains. The nucleus and the nucleolus 



