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Proceedings of the Royal Society 
results of other observers into harmony with his own, though the 
deviations from the three-zoned pillar process, which he has himself 
observed, certainly seem to throw doubt on the possibility of any 
general reconciliation of the discrepant results of authoritative 
observers being effected in this way. 
In an almost contemporary research by Yon Wiedersperg, the 
spermatozoa of rat, &c., are traced to the “ round cells ” which result 
from the repeated division of the peripheral cells of the tubules. 
An account of mammalian spermatogenesis has recently been 
given by H. H. Brown (1885). Certain cells in the most external 
layer of the tubule, next the basement membrane, seem to form 
the essentially spermatogenetic cells. These “spore-cells” are sup- 
posed to be the direct descendants of the primitive male ova. Each 
spore-cell, apparently by a process of nuclear budding, forms two 
cells, one of which divides by karyokinesis to form the more internal 
“ growing and multiplying cells,” which are the direct predecessors of 
the sperms. There are, however, other inactive cells in the tubule— 
“ the supporting cells,” and with these the young sperms become 
associated very shortly after their liberation. Brown agrees with 
Swaen and Masquelin in deriving the sperms in the Elasmobranch 
testis from primitive male ova, and the supporting cells from folli- 
cular cells, corresponding to the cells of the Graafian follicle in the 
ovary, and suggests a similar origin for the supporting cells in 
mammals. With Brown’s account a later investigation by Benda 
essentially agrees, while a research by Griinhagen seems, on the 
whole, to' corroborate Biondi. 
§ 2. Having thus summarised* the principal observations on sper- 
matogenesis, we must, as a necessary step towards clearness, collate 
the all too-abundant nomenclature, the confusion of which affords a 
suggestive index to the want of lucidity on the subject. Not only 
do we find a maze of frequently tautologous terms, such as sperma- 
togonium, spermatoblast, spermatocyst, spermatogemma, spermatocyte, 
spermatomere, spermosphere, spermoblast, and a dozen more ; 
hut the frequent use of the same term, e.g ., spermatoblast, with 
different connotation by different investigators. The subjoined 
tabular comparison, necessary for our present purpose, may not be 
without a wider use. 
* See also § Spermatogenesis in “Reproduction,” Ency. Brit., vol. xviii., 1886. 
