SPECIAL SUBJECTS. 
Gen. Sub. 29 
Cunningham, J. T. [See Reprod.] 
Description of immature testis of Myxine. 
Geodes, P. Art. Reproduction ; Encycl. Brit. 
Historical and theoretical. 
, & Thomson, J. Arthur. History and Theory of Spermatogene- 
sis. P. R. Soc. Edinb pp. 803-823, 1 pi. 
History of research, and attempt to rationalize the various modes of 
Spermatogenesis, by comparing them with parallel processes in ovum 
segmentation. 
. [See Reprod.] 
A predominant katabolism effects differentiation of male elements. 
Gilson, G. Etude comparee de la sperm atog^nese chez les Arthro- 
podes. La Cellule, i & ii, pp. 83-239, 15 double pis. 
First stage : A nucleated plasmodium ; the nuclei with fragmented 
nuclear element, multiplying by stenosis, until at a certain period indi- 
vidualization occurs, and primary “ m^trocytes ” are- formed ; in these 
the nuclear element is, sooner or later, reformed, and becomes filamen- 
tous ; karyokinesis sets in, and by binary segmentation ever smaller 
cellules spermatiques are formed. Second stage : In the protoplasm a 
special, but variable hyaline vesicle is formed ; protoplasmic processes 
often develope ; the nucleus changes in form, and also in contents, and 
eventually becomes homogeneous. Third stage : Formation of two kinds 
of spormatophores immany species ; development of spermatic cells into 
spermatozooids. 
Hoffmann, C. K. Zur Entwicklungsgoschichto der Urogenitalorgano 
bei den Anamnia. Z. wiss. Zool. xlvi, pp. 570-G43, 3 pis. 
Some general notes on first stages of spermatogenesis. 
° Jensen, O. S. Ueber die structur der Samenkorper bei Saugethieren 
Vogeln und Amphibien. Anat. Anz. i, pp. 251-267. 
Krapelin, K. Phylogenie undOntogenie derBryozoen. Biol. Central hi. 
vi, pp. 599-602 ; Ber. 59 vers. Naturf. Berlin : 1886. 
Platner, G. [See Cell.] Arch. mikr. Anat. xxvi, pp. 343-369, 1 pi. ; 
J. R. Micr. Soc. vi, pp. 216 & 217. 
With especial reference to the nuclear changes. 
. Zur Bildung der Geschlechtsprodukte bei den Pulmonaten. Arch . 
Anat. xxvi, pp. 509-621, 2 pis. ; J. R. Micr. Soc. vi, pp. 410-412. 
(1) Karyokinesis in sperm-cells of Helix ; origin of accessory nuclear 
body or nebenkern from the spindle fibres. (2) Spermatogenesis in Arion. 
From the nucleated protoplasm of the reproductive organ there arise (a) 
primitive ova ; ( h ) spermatogonia and basal cells ; (c) nutritive cells 
furnishing the yolk ; and ( d ) nuclei of the alveolar wall and of the 
follicular membrane (reserve germs for future reproductive elements). 
Sciiauinsland, H. Die Excretions- und Geschleohtsorgaue der Priapu- 
liden. Zool. Anz. ix, pp. 574-577. 
