1887] The Significance of Sex. 139 
usually has a row of four nuclei as in æ, but when division takes place the nuclei 
divide so as to furnish the daughters with the normal number (4). 
Fic. 97, a—d. Stylonychia histrio—Nussbaum, A. m. A., xxvi.—Here we have 
wo sorts of nuclei, a small spindle-shaped * paranucleus,’’ which in division presents 
k spindle-fibres and microsomata of karyokinesis, and a large nucleus whose 
“ nuclein” substance is more irregularly distributed. In a resting state (a}the para- 
nucleus is homogeneous and nearly spherical, the nucleus has small bodies in it that 
resemble the paranucleus. When cell-division takes place (4, c) both sorts of nuclei 
ivide so that the daughter-cells are multinucleate, but when these return to the 
“resting” condition the sey fuse once more, as seen ind. Here the nuclein bodies 
of the nucleus are drawn out into filaments. 
1G..97 4, a-b. pane vision of Paramecium,—tfrom article “ Protozoa” in 
Encyclopeed. Brit., by Lankester. Here the paranucleus divides into two groups of 
four each, but the nucleus Ge a up much finer and strongly suggests. beaded ng 
a Bütschli in A. m X., figures the nucleus as broken up more irregular 
G. 98, a-g. RN ~ e (a—c, f-g) and Dallingeria drysdali (d EA D 
e Jour. R. Micr. Soc., April, 1886.—After conjugation (see Fig. 131) the 
fertilized nucleus of the sp je EES a the protoplasm in ultra mi- 
croscopic particles (gemmules), and when the cyst bursts these are projected out, and 
soon grow so as to be visible to a power e fifteen thousand diameters, until final 
they attain the size and shape seen in a, then granules appear in their substance, 
and at the same time a clear zone of protoplasm (4) is secreted about this body, which 
henceforth is the nucleus (c). When division is to take place the u 
themselves in regular lines as in g, and a peculiar and simple karyokinesis follows 
(e-f), with return of granules to normal distribution in g, a daughter-nucleus. 
Fic. 99, a—c. Nucleus of Chromulina woroniana—Fisch, Z. w. Z., xlii.—The 
wall of the nucleus is thick and contains nuclein, but there is also a nucleolus which 
segments up into fine granules, while simple constriction of the nucleus ensues (a-c), 
and when the daughter-nuclei are established, these granules fuse and return by in- 
verse kinesis to the normal state. 
` Fic. 100, a-d. Nucleus of Cyathomonas truncata—Fisch, |. c,—This is thin- 
walled, sin most all the ace is in the nucleoli. In æ four of these bodies are 
seen. es raying out from the nucleolus, and the nucleus 
and nucleolus behave in division : much as if the former were a cell and the latter its 
nucleus; finally, after division (c-d), the rays disappear, and we get a simple nucleus 
with a nucleolus, 
Fic. 101, a-e. Nucleus of Cordosiga botrytis—Fisch, l. c.—We have first a clear 
_ vesicle containing a nucleolus, the latter gradually dissolves into granules (a, 6), and 
use to filaments (d), which arrange themselves parallel to one another 
like a spindle, and then the fibre-bundle constricts, followed by the nucleus (e). The 
original state is assumed by the daughter-nuclei passing ugh an inverse series of 
: : thus ae e we get successively d, c, 4, a, etc. 
Fic. » a-b. Onychodactylus acrobates—Entz, Mitt. Neap., v.; 1 Stylonychia 
PERE (from Kent, Plate 1.).—Division of nucleus and paranucleus 
during ee a The nucleus and paranucleus remain dent applied to 
each other; the latter /eads in division. The segments of the former remain united 
by a brides (c), the centre one only being severed by cell-division as in 4. 
ae 1G. 103, 6-9 “ae, Nucleus of Spirochona gemmipara—Hertwig, Jenaische Zeit- 
: jum etchornit- ig, Z 
see Gruber, Z. w. Z., xxxviii—a-c show the ameeboid powers of nuclear substance; 
