ON SPINDLE-LENGTH AND CELL-VOLUME. 45 
3. The Possible Connection between Spindle-Length and 
Cell-Volume. By C. F. U. Murex, M.Sc., F.L.S., 
F.Z.S. 
[Received October 31, 1913: Read February 17, 1914.] 
(Plates I. & II.*) 
INDEX. 
Cytology. 
Introduction. 
I have stated that in Porficula auricularia and Helix pomatia 
the ratio between the lengths of the mitotic spindle at the 
conclusion of the two spermatocyte metaphases is identical, 
or almost identical, with the ratio between the radii of two 
spheres of which the volume of one is equal to twice that of the 
other; and the same ratio has been observed by von Winiwarter 
in the spermatocyte metaphases of Man. Since each primary 
spermatocyte divides to form two daughter secondary spermato- 
cytes, and since no period of growth seems to separate their 
mitoses, the volume of the primary spermatocyte cell in the 
metaphase is presumably equal to twice that of the secondary 
spermatocyte. Connection is therefore suggested between the 
spindle-length and cell-volume at this stage. 
Although this ratio has been observed in organisms repre- 
senting three phyla of the animal kingdom, the inference is 
speculative; for coincidence may be responsible for the apparent 
connection. i pointed out in an earlier paper that only one 
generalisation seemed to have been established concerning the 
mitotic spindle, namely, that it is not a figure formed entirely 
by the action of forces at its poles. We have since found that 
its length at the conclusion of spermatogenetic metaphases 
cannot be correlated with the volume of the chromatin; and, 
if we can eventually prove that the length at this stage is 
or is not connected with the volume of the cell, we shall have 
succeeded in establishing another generalisation. 
In a paper on chromosome dimensions, published in 1912, 
I stated that increasing somatic complexity of the organism 
seemed to be accompanied by increase. of chromatin volume in 
the germ-cell. The measurements given, however, proved that 
no theory depending entirely upon a quantitative analysis can 
suffice; for, in certain cases, the difference of chromatin volume 
in widely separated organisms was found to be less than that in 
organisms belonging to sister families. 
I now intend to compare the volumes of spermatocyte cells in 
Helix pomatia, Forficula auricularia, Triton cristatus, and Man— 
organisms representing three phyla; and, in order that a com- 
parison may be possible also in organisms belonging to allied 
* Wor explanation of the Plates see p. 49. 
