416 J. E. BLOMFIELD. 
The mature spermatozoa of Helix exhibit a small pear- 
shaped head, which stains readily with picrocarmine, and 
a long, slightly flattened tail. Besides the very early stage 
of the nucleated spermatospore,! the first commencement of 
the formation of the polyplast is evident in cells with two 
or three nuclei and a corresponding slight segmentation of 
the enveloping protoplasm. In this state the testis is 
found during the winter when the animal is torpid, and no 
further growth takes place till the following spring (Plate 
XXIV, figs. 1—6). 
If the contents of the ovotestis be examined in the spring, 
in the months of May or June, the spermatospores will be 
found to have advanced, most of them, to the stage of poly- 
plasts of the ordinary mulberry-like form, consisting of pear- 
shaped spermatoblasts, one of which can be distinguished 
from the rest by the granular nature of the plasma around 
it and by the larger size of the nucleus (fig. 9 b,c). This 
nucleus also, under the action of picrocarmine, takes up a 
darker hue than that of the surrounding spermatoblasts. 
It is not so large as the nucleus of the original cell (sperma- 
tospore). 
This cell is always on the side of the polyplast, next to 
the wall of the ampulla of the gland, and it is the first 
appearance of the blastophoral cell, which, from the time of 
its appearance, undergoes. no further division, but remains 
inactive while the other spermatoblasts continue their pro- 
cess of multiplication more.or less supported by it. 
During the process of formation of the spermatoblasts the 
nuclear division appears to take place with no mathematical 
regularity. _The nuclei do not divide at the same time, so 
that an uneven number of spermatoblasts is as common as 
an even. In the early stages the cell with three nuclei is as 
common as that with two or four. It is possible that one of 
the nuclei of the three-celled form ceases to undergo further 
change and remains as the blastophoral cell, while the others 
continue their development ; but, as there are no granules or 
other characteristic marks to distinguish this body before 
the stage of eight or ten spermatoblasts, it is impossible to 
say whether this is the case or not. 
To see the remainder of the process of the development of 
the spermatozoa, the contents of a generative gland must be 
taken about the beginning of August. This appears to 
consist, as in the earth-worm, in an elongation of the soft 
1 With reference to these and other terms, see my former paper, this 
Journal, January, 1880, and also the list of terms at the end of the present 
paper. 
