312 THE AMERICAN MONTHLY [Oct. 



Nucleus of Red Blood-Corpuscle of Mammals. 



By JOHN MICHELS, 



NEW YORK. 



I have read Dr. William Moser's remarks, in the 

 Medical Record of October 20th last, relating to the 

 caryocinetic changes in the red corpuscle, with much in- 

 terest, as I there recognized various appearances of blood 

 which I discovered during examination under the micro- 

 scope about seven years ago, which interested me great- 

 ly at the time. 



Up to this date it appears to be a recognized fact, 

 taught in all text-books, that a nucleus did not exist in 

 the red corpuscle of mammals, except in the embyro, 

 and as a consequence, in certain anaemic conditions of 

 the blood. I was always unwilling to accept that con- 

 clusion, on account of the admitted importance of all 

 nuclei to cell life, and thus, as the blood corpuscles of 

 birds and reptiles always contained a nucleus at all 

 stages of their existence, it seemed highly probable 

 that they really existed in the red mammalia, and, rea- 

 soning by analogy, it seemed difficult to account for 

 their absence, especially as they had been seen in hu- 

 man blood in the foetal stage and under certain patho- 

 logical conditions. 



As I considered that the nucleus was composed of 

 protoplasm, it struck me that the stain used by botanists 

 as a reagent for this material in plants would be the 

 best to employ to demonstrate the nucleus of the red 

 corpuscle of animals, if it contained protoplasm. 



Acting on this suggestion, I made a large number of 

 human blood preparations in the following manner: 

 Placing a drop of human blood on a slide, 3x1 inches, I 

 then took another slide and drew the sharp edge rapidly 

 across it at right angles, using all the pressure possible 

 and allowing it to dry. This is the best method of ob- 



