

20 HUMAN SPERMATOGENESIS: A STUDY OF INHERITANCE. 



vanish from view. It is also to be recalled that in the fertilized egg never more 

 than one aster with one centriole arises close to the sperm head. Therefore it 

 would seem probable that the elaborate changes of the centrioles in the spermio- 

 genesis are concerned chiefly with the formation of the axial filament and changes 

 in form of the cell, and that when these changes are accomplished all but one of 



the centrioles degenerate. 



Lastly, attention may be drawn to the great range in volume of the heads of 

 normal spermatozoa, already remarked by Retzius, and found by me to be a 

 case of graded variation (fluctuation). The mass of chromatin introduced by 

 the sperm into the egg may well have causal connection with the variation in 

 the somatic persons. The sizes of the spermatozoon heads offer a clear case of 

 germinal variation of graded character; the variation of behavior of the allosomes 

 in the maturation divisions would represent discontinuous variation. 



Ballowitz, H 



LITERATURE 



1891. Weitere Beobachtungen iiber den feineren Bau der Saugethierspermatozoen. 



Bardeleben. K 



Zeit. w. Zool., LII. 



1892. Ueber Spermatogenese bei Saugethieren. Verh. Anat. Ges. 



1897. Beitrage zur Histologic des Hodens und zur Spermatogenese beim Menschen 



Branca, A 



Arch. Anat. Phys., Anat. Abth., Suppl. 

 Weitere Beitrage zur Spermatogenese beim Menschen. Jena. Zeit.. XXXI 



1909. Sur la manchette caudale dans la spermiogSnese humaine. Bibl. Anat., XIX 



Broman, J 



mitoses 



C. R. Assoc. Anat., XII. 



1901. Ueber gesetzmassige Bewegungs und Wachsthumserscheinungen (Taxis- und 



enformen) 



m. Anat.. LIX 



iono?' Tik at yP lsche Spermien (speciell beim Menschen) etc. Anat. Anz., XXII. 

 19026. Ueber Bau und Entwickelung von physiologisch vorkommenden atypichsen 



DUESBERG, J 



mien. Anat. Hefte, XVIII. 



Jnno" ? U le non \ bre , de8 chromosomes chez l'homme. Anat. Anz., XXVIII. 

 1908. La spermatogenese chez le rat. Leipzig. 



GUTHERZ, S. 



1911. Ueber den gegenwartigen Stand der Heterochromosomenforschung. Sitzungsb. 



Ges. Naturf. Fr. Berlin. 



Guyer, M. F 



^~ ^"^ ■■• ^* w a &. v> v, 



Jensen, O. S. 



1887. Unl 



KOLTZOFF, N. K 



Man. Biol. Bull.. XIX 



orper der Saugethiere. etc. I. Arch, m 



T »•»« 19 ° 8 ' StU * dien tiber die Gestalt der Zell e- II. Arch. Zellf II 



Leeuwenhoek, A. de ' 



1679. Observations de 



XII « 



Meves, F. 



Phil. Trans. R. Soc. London, 



1897. 



Achsenfaden 



Anat. Anz., XIV. 



Mensc li 



1899. Ueb^u n k r„^^ ( l^L A !?i'-«-- 



m An«+ ttv w—** «ci Samenfaden des Meerschweinchens. Arch. 



MoliA J. Van. ' V ' 



1905 



T.» Z™£f?^L d ™ «'<««wHL U Cellule. XXIII 



Ibid.. XXVI 



