SPINDLE-LENGTH AND CELL-VOLUME. 49 
this is so, why has the ratio in question been observed in Helia: 
pomatia and Man 2 
I hope to deal with these explanations in a subsequent paper. 
In the meantime, the proposition remains a suggestion. 
BIBLIOGRAPHY. 
Meer, C. F. U. 
1911. The Spermatogenesis of Stenobothrus viridulus. Journ. 
Linn. Soc., Zool. vol. xxxii. 
1912. A Metrical Analysis of Chromosome Complexes, show- 
ing Correlation of Evolutionary Development and 
Chromatin Thread-width throughout the Animal 
Kingdom. Phil. Trans. Roy. Soc. ser. B, vol. cciii. 
The Correlation of Somatic Characters and Chromatin 
Rod-lengths, being a further Study of Chromosome 
Dimensions. Journ. Linn. Soce., Zool. vol. xxxii. 
1913. The Problem of Mitosis. Quart. Journ. Mier. Sci. 
vol. lviii. Part 4. 
The Metaphase Spindle in the Spermatogenetic Mitoses 
of Forficula auricularia. Idem, vol. lix. Part 2. 
» Ihe Length of the Mitotic Spindle in the Spermatocyte 
: Metaphases of Helix pomatia. Proc. Roy. Soc., ser. B, 
vol. Ixxxvii. No. 594. 
99 
79 
EXPLANATION OF THE PLATES. 
PrateE I. 
Figs. 1-8. Polar and lateral views of spermatocyte cells of Tiiton cristatus, in 
the metaphase and earliest anaphase. 
9. Polar view of equatorial plate in primary spermatocyte metaphase of 
Stenohothrus viridulus. 
10,11. Polar views of equatorial plate in primary spermatocyte metaphase of 
Stenobathrus curtipennis. 
12. Lateral view of spindle in primary spermatocyte metaphase of Sfeno- 
bothrus curtipennis; the odd or heterotropic chromosome is seen 
passing undivided toward the lower pole of the figure. 
Prats II. 
Fig. 18. Polar view of equatorial plate in primary spermatocyte metaphase of 
Horficula auricularia. 
14, Lateral view of spindle at conclusion of primary spermatocyte metaphase 
of Forficula auricularia. 
16. Polar view of equatorial plate in secondary spermatocyte metaphase of 
Forficula auricularia. 
15,17. Lateral views of spindle in secondary spermatocyte metaphase of 
Forficula auricularia. 
18,19. Polar views of equatorial plate in primary spermatocyte metaphase of 
Helix pomatia. 
20,21. Lateral views of spindle in primary spermatocyte metaphase of Helia 
pomatia. 
22. Polar view of equatorial plate in secondary spermatocyte metaphase of 
Helix pomaéia. 
23. Lateral view of spindle at conclusion of secondary spermatocyte 
metaphase of Helix pomatia. 
24. Lateral view of spindle in earliest secondary spermatocyte anaphase of 
Helix pomatia. 
25. Divisions of stage micrometer, 10 « apart, showing magnification of 
figs. 1-13 and 15-24. 
Proc. Zoou. Soc.—1914, No. Was 4 
