SPERMATOGENESIS OF THE HORSE. 313 



\ 



^-element in the primary spermatocyte division stages, makes 

 its appearance during the growth period and can be traced for- 

 ward until it is finally thrown off with the ball of cytoplasm in 

 the developing spermatozoon. It does not contribute in any 

 visible way to the formation of the spermatozoon. 



LITERATURE CITED. 

 Faust, E. C. 



'13 Size Dimorphism in Adult Spermatozoa of Anasa tristis. BIOL. BULL., 



Vol. XXV., No. 5, Oct., 1913. 

 Guyer, M. F. 



'10 Accessory Chromosomes in Man. BIOL. BULL., Vol. XIX., No. 4. 

 Jordan, H. E. 



'ii The Spermatogenesis of the Opossum (Didelphys virginiana) with Special 

 Reference to the Accessory Chromosome and the Chondriosomes. Archiv 

 fur Zellforschung, 7. Band, i. Heft. 

 Paulmier, F. C. 



'99 The Spermatogenesis of Anasa tristis. Jour. Morph., XV., supl., pp. 223- 



272. 

 Wilson, E. B. 



'13 A Chromatoid Body Simulating an Accessory Chromosome in Pentatoma. 



BIOL. BULL., Vol. XXIV., No. 6, May, 1913. 

 Wodsedalek, J. E. 



'13 Spermatogenesis of the Pig, with Special Reference to the Accessory Chro- 

 mosomes. BIOL. BULL., Vol. XXV., No. i, June, 1913. 



'13 Accessory Chromosomes in the Pig. Science, n.s.. Vol. XXXVIII., 

 No. 966, pp. 30-31. 



