AGA Chromosomes of Anasa Tristis and Anax Junius 
THE GrowtH Perrtop.—The growth period has not been followed 
throughout in all the detail that is desirable, and the important question 
of the character of the synapsis must for the present be left undecided. 
Preceding the contraction-phase a stage is found where the chromatin 
appears in the form of fine threads scattered throughout the nucleus or 
more or less massed in loose tangles. Some of these strands are V or 
Y-shaped, or are seen lying in separate pairs or as irregular crosses (Fig. 
2, F.) The appearance might readily be interpreted as the result of a 
longitudinal conjugation of univalent chromosomes which are now open- 
ing out to form elongated loops or ribbons. In view of the work of 
v. Winiwarter, 00, the Schreiners, 04-06, Lerat, 05, Janssens, 05, Bonne- 
vie, 05-07, Stevens, 05, 06, and others, who have brought forward evi- 
dence in support of parallel conjugation, it is entirely possible that a 
more careful study of this and earlier stages in the growth-period of 
Anax might throw light upon the true nature of synapsis in this insect, 
but at present the evidence is insufficient for a demonstration. 
The odd chromosome, as a dense nucleolus-like body, is quite conspicu- 
ous at this stage, staining deeply in both hematoxylin and safranin, and 
is frequently found to be constricted into a dumb-bell shape (Fig. 2, F, 
h). It does not occupy a constant position in the nucleus, sometimes 
lying near the membrane, at other times at any point within the nuclear 
area. Often it is seen close against the plasmosome, while as often it may 
lie at quite a distance from it. 
This stage is followed by the contraction-phase (Fig. 2, G), in which, 
however, the chromosomes never become condensed into a compact mass. 
The threads now appear much thicker and longer than at an earlier 
period and are usually arranged in long, loose loops, the ends of which 
are more or less directed toward one pole of the nucleus, constituting the 
so-called “ bouquet-stage.” Curiously enough, the longest and thickest 
ribbon, which is the one that will give rise to the largest tetrad later on, 
frequently lies outside the “bouquet” and is seen stretching half-way 
around the nucleus close against the membrane, as shown in Fig. 2, G. 
This elongated chromosome is often interrupted at its middle point, as 
are, in fact, some of the looped threads, which consequently exhibit a 
bivalent nature. The break, moreover, is found to persist from now on 
to the time when the final condensation of the chromosomes takes place 
in the formation of the crosses. It may represent, of course, the line of 
suture between two univalent chromosomes conjugating end to end, or 
it may be equally well interpreted as the point of contact between the 
