SPECIAL SUBJECTS. 
Gen . Sub. 27 
number of cells. These are liberated by rupture, the inferior becomes 
the ovule, the others are vitellogenous. 
c 'Plagniol, E. de. Embry ologie de l’CEuf du Ver a soie. Privas. 8vo, 
55 pp., pi. 
Platner, G. Zur Bildung der Geschlechtsprodukte bei Pulmouaten. 
Arch. Mikr. Anat. xxvi, pp. 599-621, 2 pis. ; J. R. Micr. Soc. vi, 
pp. 410-412. 
Oogenesis of Avion and Ilelix. Polar globules in Avion. Three always 
— as result of division of one of the original two. Process consists 
essentially in removal of nuclear constituents, to be replaced by male 
nucleus. 
Sabatier, A. Sur la morphologie de l’ovaire chez les Insectes. C.R. 
cii, pp. 61-63. 
In insect ovaries with large nutritive cells the primitive ovule gives 
rise, endogenously within its protoplasm, independent of germinal 
vesicle, to the nuclei of the follicular, and later to those of the nutritive 
cells. Both are eliminated elements. 
. Sur la morphologie de l’ovaire chez les Insectes. T. c. pp. 267-279 
& 441-443. 
Sciiauinsland, H. Die Excretious- und Geschlechts- organe der Pria- 
puliden. Zool. Anz. ix, pp. 574-577. 
°Sciiultze, O. Ueber Reifung und Befruclitung des Araphibieneies. 
Anat. Anz. i, pp. 149-152. 
Seeliger, O. Die Knospung der Salpen. Jen. Z. Nat. xix, pp. 573-677, 
10 pis. 
Intev alia — Follicular cells not from ovum,— opposition to observation 
of Fol, Ulianin, Roule, Sabatier, &c. The cells which form others by 
division or by budding are not yet to be reckoned as ova. Theoretical 
considerations as to follicular cells, polar cells, &c., and the general alter- 
nation of generations in Metazoa. 
Sedgwick, A. The Development of the Cape Species of Pevipatus. 
Q. J. Micr. Sci. xvi, pp. 175-212, 3 pis. 
Sponge-like structure of ovum ; description of polar globules ; con- 
tinuity of nuclear and extra-nuclear reticulum ; nucleus of fertilised 
ovum differs from the cell protoplasm only in the way the chromatin of 
the network behaves ; the endoderm cells at first without distinct 
nucleus ; the segmented ovum a syncytium. 
Stuiilmann, F. Die Reifung des Arthropodeneies. Biol. Ceutralbl. vi, 
pp. 397-402 ; Ber. Freiburg Ges. (1886). 
Some of uniform nuclei of germinal layer differentiate towards ova; 
germinal vesicle moves to periphery, and seems to get flattened against 
follicular epithelium. No passage of chromatiu bodies from nucleus, as 
in many insect ova. Apparent absence of polar cells in large ova 
rich in yolk. Expulsion of polar cells at a very early stage, before egg 
