DEVELOPMENT OF THE OAPE SPECIES OF PERIPATUS. 207 
have examined other segmenting ova to see if the fact was one 
of general application, with negative results. 
The cells of segmenting ova are generally so closely applied 
together and the protoplasmic strands so hidden by food-yolk, 
that it is difficult to be certain of the point either way. But 
with ova in which the segments are slightly separated from one 
another—and I believe there are such though I have never seen 
them—the observation ought to present no special difficulty. 
Indeed it is a well-known fact that an incomplete separation 
of the cells is found in the early stages of the segmentation of 
centrolecithal eggs; but it has always been assumed that this 
was a temporary phase, and that the segments eventually sepa- 
rated. We now know, thanks to the researches of Heathcote 
(4), that this separation does not occur in the centrolecithal egg 
of the Myrapod, Julus; and it seems to me extremely probable 
that his results for this form will be found on careful examina- 
tion applicable to other similar ova. 
BIBLIOGRAPHY. 
1. Fremuine, W.—‘ Zellsubstanz, Kern und Zelltheilung,’ Leipzig, 1882. 
2. Fratront, J.—‘ Archives de Biologie,’ vol. v. 
3. GruBer, A.—‘ Kerne u. Kerntheile bei den Protozoen,” ‘ Zeit. f. w. 
Zool.,’ Bd. xl. 
4. Hratucotr, F. G.—The Development of Julus,” ‘ Proc. Royal Soc., 
1886. 
5. Herrzmann. J.— Untersuch. iib. d. Protoplasma,” and ‘“ Das Verhalt- 
niss zwischen Protoplasma u. Grundsubstanz im Thierkérper,” ‘ Sitz- 
ungber d. Kais. Akad. Wiss.,’ Wien, Bd. lxvii, 1873. 
6. Hurton, Captain F. W.—“‘On Peripatus nove-zealandia,” 
‘Ann. and Mag. Nat. Hist.,’ 4th ser., vol. xviii, 1876. 
7. Jicxent, C. F.—“ Ueber die Kernverhaltnisse der Infusorien,” ‘ Zool. 
Anzeiger,’ 1884. 
8. Kennet, J.—‘‘ Entwickelungsgeschichte von Peripatus Edwardsii,” 
‘ Arbeiten u. d. 2. d. d. Wurzburg,’ Bd. vii. 
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