1887] The Significance of Sex. 17 
having wesc the same reticulate structure. Some of the nucleoli are dividing 
by simple constriction. 
Fic. 3. Piette BREE cell of an insect—Carnoy, p. 190.—The reticulate 
nucleus is slung by a net-work, whose radial trabeculz are the more pronounced ; 
they branch sues ee eriphery of the cell 
Fic. 4. Jntestinal epithelium from an insect A p- 195.—The granules 
in the cytoplasm have been indicated in`some sectors, and the reticulum in others. 
The heavy nuclear reticulum, containing the chromatin, has contracted under the 
action of the chrom-aceto-osmic mixture of Flemming, and reveals a fine reticulum of 
achromatic protoplasm otherwise obscured by the presence of the chromatic reticulum 
(or filament, as the case may be). 
Fic. 5. Giant-cell from marrow of rabbit—Carnoy, p: 262. 
Fic. 6. oe Vorticella—Carnoy, p. 261.—In å the nucleus has divided into 
four. 
ns 7- Nucleus of Stentor polymorphus—Carnoy, p. 260. 
G. 8. Nucleus of Monas vivipara—Biitschli.—Microsomata of various sizes are 
ate by processes so as to form a regular net-work. 
Fic. ucleus of Ceratium tripos—Biitschli.—One of the nucleoli has an in- 
ternal ror i other is ot having only a surface reticulum. 
Fic. 1 s of Ceratium tripos—Biitschli.—No nucleoli present: a is an 
_ section borers the side, Fi is a view of the ventral igen The microšomata are 
trung in a row on each of the dorso-ventral filamen 
Fic. r1. Tentacle of Noctiluca dese eki. 
Fic. 12. Diagram illustrating the structure of striped muscle—Melland, Q. J, 
M. S., 
See met 93, d—Van Beneden, A. B., iv.—Contraction and amceboid movement 
accompanied, ie caused, by mutual attraction of the microsomata. 
Fic. 13. Nuclein filament from a gland-cell of an insect—Carnoy, p. 233.—The 
i arranged in a anise imbetided in the surface of the 
G. 14, a. A nucleus of Ameba proteus—Gruber, Z. w. Z., xlii—The chromatin 
granules are largest peripherally. In 6 (Z. w. Z., xl.) theta is a differentiation of a 
large central nucleolus with fine granules from a surface membrane of large, closely 
united microsomata, At times the microsomata are reduced to so fine granules that 
only a diffuse staining results. 
Fic. 14, c. Chenia teres Gruber, Z. w. Z., xl.—The chromatin granules have 
grown from invisible poi 
Fic. 15. Tracker lapses ‘erus—Gruber, Z. w. Z., xl.—Like Fig. 14, this” 
cell (rhizopod) is multinucleate. In æ nucleoli appear in each nucleus; in å the 
ram have ius ae to the state of free microsomata that divide up finer and 
Fie. 16. Haliomma erinaceus—Biitschli, after Hertwig.—The central capsule only 
is shown, with its large central nucleus and peripheral smaller nuclei budded from 
the central one, which has itself peripheral “ nucleoli” that resemble the sl 
“awer” o 
Fic. ees Central capsule of Acanthamera. a, = after eea oe 
‘Fic. 18. Central « se PRG OON ee r Tee oes ie ENT ON hg be 
E Deg e saturn Hertwig, et 
VOL. XXI.—NO. I. a a = 
