314 Chromosomes in the Spermatogenesis of Anasa Tristis 
PuHotos. 20 To 27. Illustrating one type of preparation for the first sper- 
matocyte division. The photographs show successive stages of the ring 
opening to form the metaphase. Through all the steps of this process, the 
eccentric chromosome maintains a position more or less detached from the 
other chromosomes, It can be recognized on the extreme left of Photos. 20 
to 23, and on the extreme right of Photos. 25, 26, and 27. 
PuHotos. 28 To 32. Early anaphases of the first division. In 28, 29, and 
30 the eccentric is on the left of each group of chromosomes. In Photos. 30 
and 32, all the ten large chromosomes, including the eccentric show a trans- 
verse as well as a longitudinal furrow. 
PLATE III. 
PuorTo. 1. Late anaphase or telophase of first division. Eleven chromo- 
somes are shown at the pole on the right while only 10 have reached the 
opposite pole, the eleventh (half of the divided eccentric chromosome), 
lagging midway between the poles. 
PuHotos. 2 AND 3. Telophase of first division, showing both poles of the 
spindle. The position of the daughter eccentric chromosomes on the left of 
each group, demonstrates their slightly retarded division. 
PuHoto. 4. Telophase of first division. Ten chromosomes are clearly 
shown at each pole, with the divided eccentric lagging between the poles, one 
of the daughter eccentrics showing a distinct transverse furrow. 
Puorto. 5. Two telophases of the first division. In both preparations the 
eccentric chromosome has lagged in division, and at each pole the daughter 
eccentric shows an exaggerated transverse furrow. See p. 294 for further 
description. 
Puotos. 6 AND 7. Telophase of first division showing the undivided eccen- 
tric chromosome lagging between the poles. (See photo. 5 for a little later 
stage.) Compare these with Photos. 33, 34, 36, 37, 38, and 39 for similar 
phenomenon in second division. 
PuHotos. § AND 9. Telophase of first division. In each preparation one of 
the daughter eccentric chromosomes is lagging midway between the poles. 
Puoro. 10. Telophase of first division. Eleven chromosomes shown at each 
pole, all, even the lagging daughter eccentric chromosomes, showing a trans- 
verse furrow. Our preparations show at both poles of these first spindles 
the same remarkable uniformity of the grouping of the chromosomes char- 
acteristic of the late first prophase or metaphase. See Photos. 11, 12, 13, and 16, 
Plate II. And we demonstrate this same arrangement of the chromosomes 
at the telophase of the second spindle (see Photos. 33, 35, 36, 38, and 43, 
Plate III). 
Puoro, 11. Later stage of the type of retarded division of the eccentric 
chromosome foreshadowed in Photos. 4, 8, and 9, which results in only one of 
the daughter eccentrics being retarded in reaching the pole—the whole figure 
bearing a suggestive resemblance to the demonstration offered in other forms, 
that one chromosome passes over undivided to one pole. 
