OBSERVATIONS ON THE CYTOMORPHOSIS OF 

 THE GERMINAL AND INTERSTITIAL CELLS 

 OF THE HUMAN TESTIS 



Don W. Fawcett and Mario H. Burgos 



Department of Anatomy, Harvard Medical School, Boston, Massachusetts 



The growth of our knowledge of the histophysiology of the 

 testis has been closely tied to the development of new methods 

 for the study of its structure. The principal events in spermato- 

 genesis were carefully worked out in the late 1800's on tissues 

 prepared by classical cytological staining methods (Lenhossek, 

 1898 ; Meves, 1899) and further refinements of these procedures, 

 combined with keen observation under the light microscope, 

 have continued over the years to disclose valuable additional 

 details (Duesberg, 1909; Gatenby, Beams and Woodger, 

 1921; Gresson and Zlotnik, 1945). Of late, the phase contrast 

 microscope has provided a means of confirming, on living 

 cells, many of the earlier observations made on fixed material 

 (Gresson, 1950; Austin and Sapsford, 1951). The use of modern 

 histochemical staining reactions has permitted a partial 

 chemical characterization of certain cytoplasmic components 

 of the germinal and interstitial cells (Montagna, 1952; 

 Mancini, Nolazco and De la Baize, 1952; Leblond and Cler- 

 mont, 1952). Improvements in methods of fixation and micro- 

 tomy have now made it possible to bring the high resolving 

 power of the electron microscope to bear upon the remaining 

 problems in the finer structure of the testis (Watson, 1952; 

 Challice, 1953). The present paper summarizes some results 

 of the application of this powerful new tool to the study of 

 the complex cell transformations in spermatogenesis and the 

 cycle of development and ageing of the human interstitital 

 cells. 



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