WILCOX: SPERMATOGENESIS. 17 
division of the spermatogonia and the first division of the spermatocytes, 
He maintains that the first division of the spermatocytes is a reduction 
division and the second an equation division. His number relationships 
for the chromosomes are hence the following : — 
Spérmatogónia "aan, Sp | BORA WP M 
Spermatocytes, Ist order, 12 bivalent rings . . . 24 
Spermatocytes, 2d order . . . . . . . . . 12 
AAA Vi nol al de irr o ie 
The only reference by Henking to rings of the value of four chromo- 
somes is in this sentence: “Ich mache besonders auf die mit vier Ver- 
dickungen versehenen Ringe 1 und 2 in Fig. 20 aufmerksam." The 
bwo rings to which Henking refers contain each four nearly spherical 
chromosomes, and these, I believe, are the only instances in which 
Henking recognized the real value of chromatio rings. Each ring con- 
tains four chromatie elements, each half-ring two elements, and since 
these two elements are separated from each other at the second sper- 
matocyte division, this, contrary to his conclusion, is just as truly a 
reduction division as is the first. But Henking objects to this in- 
terpretation: “Es findet hier also keine Reduction statt, sondern eine 
gewöhnliche Aequationstheilung, welche jedoch hier schon von fernher 
vorbereitet war." But if each ring has the value of four, not simply 
two, chromosomes, the same argument could be applied to the first as 
well as the second spermatocyte division, as Brauer (93) has already 
done. The soundness of these objections will be considered in connec- 
tion with Brauer's paper. 
Hicker (’92" and '93) has seen ring formation and Vierergruppen 
in the oógenesis of several marine Copepods. In the genera Euchata, 
Calanus, Cyclops, Diaptomus, Canthocamptus, and Heterocope, he main- 
tains «hat “zwischen die letzte Theilung der Ureizellen und die erste 
Theilung der Reifungsphase ist kein feinfadiges Ruhestadium des 
Kernes (Keimblüschenstadium) eingeschaltet.” In the eggs of some 
females this resting stage is passed over, in others not. In those females 
in which the resting stage in oögenesis is twice omitted, i. e. both before 
and after the formation of the first polar globule, Hücker (92) sug- 
gests, as a motive for the omission of tho first resting stage, that in thig 
way "im Mikrokosmus des regenerativen Lebens eine weitgehende 
Anpassungsfähigkeit zur Geltung gelangt." This omission, then, is & 
biological adaptation. "The maturation of the egg is thus brought about 
sooner. This explanation is mentioned, because it has a direct bearing 
upon any interpretation of the rings, as will soon be seen. Häcker 
VOL, XXVII. — NO. 1. 2 
