266 
Sitbiev I. Kornhauser 
cliromosomes coutract, the short arms of the Grosses l)ecome snialler. 
Remnants of them remain for some time (Fig. 116); but they disap- 
pear before the dissolution of the nuclear membrane. The quadripar- 
tite form of the tetrads is usually lost in the last stages'of contraction 
(Fig. 117). 
When the cliromosomes remain connected at both ends (Figs. 108, 
109), either rings or figure-eight tetrads are formed (Plate XX, Figs. 110 
tü 112). The Connection which is to remain until the complete Separation 
of the chromosome in the first spermatocyte division shows an oval open- 
ing between the points of union (Figs. 110, 111). The other ends of the 
two cliromosomes are attached to each other less intimately — nierely 
by fine fibers, which are stretched apart (Plate XX, Figs. 113, 115) 
in the forniation of the double-rod tetrad of the first division (Fig. 117 
to 119). The rings are not formed by a secondary approximation of 
the ends of two ribbon-like chromosomes, but are the resiüt of the per- 
sistence of the union between the ends of the chromosomes which united 
in pairs parallel to each other and then in the strepsinema separated 
only in the region between the two ends. One of these persisting Con- 
nections is lost before the spindle is formed, the other at the anaphase 
of the first division. Thus this first maturation division separates whole 
chromosomes which are connected end to end. and is therefore a pre- 
reduction division. 
If oiie compai'es the macrochromosome tetrad of Anifhiscepa^) 
hivittata Say, with that of Enchenopa one finds very iuteresting similaiä- 
ties and differences. The large tetrad in this fulgorid arises froni two 
very long spermatogonial chromosomes. 
The chi-oniosomes of the prophase of the fiist spermatocyte division 
before condensing and splittmg longitudinaUy, show points of connection 
at both ends (Figs. B and C). Later it can be seen that one of these 
pomts of Union (Fig. D, right hand side) broadens considerably iiiore 
than the other and shows an oval opening. This union doubtless corres- 
ponds to that characterized by the short arms in cross-shaped tetrads, 
such as shown in Figure 114 (Plate XX). Unlike E. curvata and E. 
hinotata, the ring form is usually not lost in Amphiscepa when the chronio- 
somes coutract, but both ends remain connected. The interchromosonial 
area - - the opening of the ring — (Fig D) decreases, changes froni a 
circle to an oval (Fig. E), and fmally to a thm slit-like opening, which 
®) I am indebtcd to Miss Axnie P. Hexchmax for the use of her very excelleiit 
preparations of Amphiscepa, from which figures D to H were drawn. 
