28 den. Suh. tilflNiiiiUL subjects. 
[Zacharias, 0.] Ueber partiello Befruchtung. T. c. p. 368. 
— — . Die feiuern Yorgaiige boi dor Befruchtung dos tierischen Eies, 
Opx cit. vii, 21, pp. 659-662. 
Besides the normal process of fertilisation, it frequently happens in the 
ovum of Ascaris that the sperrmnucleus divides into two ; each half 
unites with half of the female pronucleus, and each product of union 
assumes nuclear (pronucleus-like) form. 
3 . Sperm atoge n esis. 
Ballowitz, E. Untersuchungon iiher die Struktur der Spermatozoen, 
zugleicli ein Beitrag zur Lehre vom feinern Bau der contraktilen 
Elemente. Arch. mikr. Anat. xxxii, pp. 401-473, 5 pis. 
The minute structure described in detail : the structure of the lash, 
the fibrillar character of the axial filament, the development of the spiral 
fringe, the nature of the head. 
c Bergonzini, 0. Coutributo alio studio della spermatogenosi nei Yerte- 
brati. La Rassegna sc. med. Modena, iii, 7, pp. 337-344. 
° . Contribuzione alio studio della spermatogeuesi. Atti. Soc. 
Mod. Mem. vii, pp. 62-69. 
Biondi, D. Ueber die Entwickelung der Samenfaden beim Menschen. 
J. Ber. schles. Ges. lxv, pp. 35-38. 
Bolles-Lee, A. La spermatog6n&se chez les Ch^tognathes. Cellule, iv, 
1, pp. 107-133, 2 pis. 
“ Polyplasts,” from division of original male and female cell, bccomo 
free in coelome, completely segment into spermatocytes grouped round 
a blastophore. The ‘Nebenkern.’ Sperms have procephalic filament, 
tail, and undulatory membrane. In the “ polyplast ” the head is 
turned outwards, the accessory nuclear body inwards, or towards the 
blastophore. 
°Brazzolo, Floriano. Recerche sulla istologia normale e patologica 
del testicolo : nota li, La cariocinesi nel testicolo normale. 
Bologna : 4to, 23 pp., 1 pi. (Ex Mem. Acc. Bologn. ix.) 
VON Ebner, Y. Zur Spermatogenese bei den Siiugethieren. Arch. mikr. 
Anat. xxxi, pp. 236-292, 3 pis. 
Resumption of the author’s investigations of seventeen years ago. The 
history and terminology of the subject. The relation of the basal nuclei 
of the spermatoblasts to the cells of Sertoli and the spermatogonia of 
v. la Valette St. George. The true spermatogonia are the cells of the 
peripheral layer ; these grow into spermatocytes ; each of the latter 
divides into four spermatides ; numerous spermatides become associated 
with a follicular cell, and form a spermatogemma. 
