SPERMIOGENESIS OF HELIX ARBUSTORUM. 
319 
4. The reduction. 
The reduction of Helix was first studied by Platner (93). According 
to him the reduction takes place by the telophase of the first matura¬ 
tion division remaining out, and the chromosomes arranging themselves, 
without going into resting stage, in the equatorial plate of the second 
maturation spindle which has formed in the mean-time. The halves of 
the chromosomes pass into different daughter cells, i. e. into the 
secondary spermatocytes which then have half as many chromosomes 
as the primary spermatocytes. 
According to vom Bath (99) the reduction of Helix agrees with 
that of Gryllotalpa, i. e. its chromatin masses into 12 tetrads the 
constituent parts of which pass during the reduction period into four 
different daughter cells which have then he reduced number (=12) of 
chromosomes. In Helix, as mentioned above, no tetrads arise, and if 
its spermatocytes have tetradlike bodies they cannot be identified with 
the true tetrads, especially with those of the Arthropoda. Becent in¬ 
vestigators have shown that the results of vom Bath have only the 
value of a scheme, and also his figures are in the highest degree dia¬ 
grammatic, therefore his investigations are not so important in the 
question of reduction as formerly believed. Neither former investiga¬ 
tors, nor the present author has found in Helix such microscopical 
figures as are similar to those given by vom Bath from Gryllotalpa. 
vom Bath’s views exercised great influence also upon those of 
Prowazek (98). The chromatin of Helix — according to this latter 
author — mass themselves into 12 chromosomes, or 12 chromosome 
groups, which represent tetrads. The constituents parts of the tetrads 
are rarely to be seen, and mostly only two parts are distinctly visible 
which are coalesced either at their ends, or in the middle, and thus 
arise x-, or o-shaped bodies. The tetrads divide during the maturation 
divisions into four parts, viz. in the first division longitudinally, in the 
second «apparently» transversely and thus get the four spermatids 12 
chromosomes, which is equal to their reduced number. 
Bolles Lee’s investigations (10) gave a quite different result. The 
spermatogonia of Helix pomatia — according to this author — have 
24 chromosomes, and so many have also the primary spermatocytes. 
The chromosomes of the spermatocytes are ovoidal, and divide in the 
first maturation division transversely, thus the secondary spermatocytes 
have also 24 chromosomes. The second maturation division takes place 
in quite the same manner as the first, therefore the number of the 
chromosomes does not become reduced at all. 
