CHROMOSOMES IN MAN 



H. L. WIEMAN 

 Zoological Laboratory, University of Cincinnati 



TEN FIGURES 



INTRODUCTION 



The literature dealing with the subject presents a wide range 

 of possibilities in reaching conclusions regarding the nature and 

 number of the chromosomes of man. Some of the earlier results 

 may be dismissed, perhaps, on the ground of imperfect technic 

 or unfavorable material, but the same means of elimination can 

 not be used in removing difficulties in more recent observations. 



Bardeleben in 1892, the first to make any definite statement 

 of the number of chromosomes in man, claimed it to be sixteen. 

 The number twenty-four was first recorded by Flemming in 1897, 

 if one may disregard the earlier work of Hansemann who also 

 found twenty-four in some cases, but in others eighteen and 

 forty. Wilcox ('00) reported eighteen, with variations of fifteen 

 and nineteen; but whether this represents the diploid or haploid 

 number, he does not say. In 1906, Duesberg, on the basis of 

 finding twelve chromosomes in the first spermatocyte division, 

 corroborated Flemming's conclusion that twenty-four is the unre- 

 duced number. In the same year Moore and Arnold described 

 sixteen gemini in the first spermatocyte metaphases, which would 

 make the diploid number thirty- two. ' 



In 1910, Guyer published the observation of twenty-two chro- 

 mosomes in the human spermatogonia. According to him, in 



1 In a study of the cytology of malignant growths in man, Farmer, Moore 

 and Walker (Proc. Roy. Soc, B vol. 77, 1906) note the frequent occurrence in 

 mitoses of 32 chromosomes which they consider the normal somatic comple- 

 ment. 



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