Lengths in the Spermatocyte Metaphases of Helix pomatia. 197 



BIBLIOGRAPHY. 



Demoll, R., 1912. " Die Sperniatogenese von Helix pomatia, L.," ' Zool. Jahrb.,' 

 Supplement XV, vol. 2.* 



Meek, C. F. U., 1912. " A Metrical Analysis of Chromosome Complexes, showing Corre- 

 lation of Evolutionary Development and Chromatin Thread-width throughout 

 the Animal Kingdom," 'Phil. Trans.,' B, vol. 203. 



Meek, C. F. U., 1912. " The Correlation of Somatic Characters and Chromatin Rod- 

 lengths, being a Further Study of Chromosome Dimensions," ' Journ. Linn. Soc. 

 Zool.,' vol. 32. 



Meek, C. F. U., 1913. " The Problem of Mitosis," ' Quart. Journ. Micro. Sci.,' vol. 58, 

 Part IV. 



Meek, C. F. IT., 1913. "The Metaphase Spindle in the Spermatogenetic Mitosis of 



Forfictda auriodaria," ibid., vol. 59, Part II. 

 Winiwarter, H. von, 1912. " Etudes sur la Spermatogencse humaine," 'Arch, de Biol.,' 



vol. 27. 



EXPLANATION OF THE PLATE. 



« 



Fig. 1. — Polar view of primary spermatocyte complex. 



Figs. 2-12. — Lateral views of spindle at conclusion of the primary spermatocyte meta- 

 phase, showing completed constriction of chromosomes. In each figure the 

 length of the spindle, estimated from the magnification, is 15'3 



Fig. 13. — Polar view of secondary spermatocyte complex. 



Figs. 14-23. — Lateral views of spindle at conclusion of the secondary spermatocyte meta- 

 phase, showing completed constriction of chromosomes. In each figure the 

 length of the spindle, estimated from the magnification, is 12"1 /x. 



Fig. 24. — Divisions of stage micrometer, 10 p apart, showing magnification of figs. 1-23 

 inclusive. 



* A list of publications dealing with the spermatogenesis of Helix is given in the 

 bibliography of this paper. 



