GERM CELLS OF COELENTERATES 605 



the eggs in, or attached to, the ovary was there any sign of 

 fertilization or even of spermatozoa. 



Chromosomes. Since the chromosomes in the maturation mi- 

 toses are large, it is possible to make some study of their behav- 

 ior. In referring to the chromosomes of the equatorial plate 

 of the last oogonial mitosis (figs. 5, 6) attention was called to the 

 difficulty of grouping these bodies in pairs, and it was suggested 

 that in synapsis the pairing must be between unlike chromo- 

 somes. If this be the case, the two maturation mitoses should 

 demonstrate it, since one of the divisions should separate whole 

 chromosomes while the other would involve splitting of the 

 chromosomes. Figures 19 to 24 are metaphases of the first 

 maturation mitosis and figures 25 to 27 are polar views of the 

 equatorial plates of the same mitosis. In each of the figures 

 20a, 21a, 22a, at least one chromosome shows the two parts 

 unequal in size. Also figure 23 (which includes only a portion 

 of the spindle) shows that two chromosomes, in dividing, have 

 formed parts which are not quite equal in size. The differences 

 in these cases are not great, greatest in figure 20a, but they exist 

 and appear to be characteristic. In the equatorial plates it is 

 difficult to see any difference, but on account of the shape of the 

 chromosomes and the fact that they do not lie in the same plane, 

 slight differences would probably not be apparent. 



Figures 15 and 29 represent the group of chromosomes at the 

 inner end of the first maturation spindle and in them a split is 

 already occurring in preparation for the next division. In both 

 these cases there is no doubt of the equivalence of the two parts 

 of the chromosomes. The side view of the metaphase of the 

 second spindle shown in figure 17 also suggests an exact halving 

 of the chromosomes, and polar views of the second maturation 

 mitoses (fig. 34) indicate the same thing. Perhaps figure 23 is 

 the clearest case; here the two chromosomes are just separating 

 in the first division but the second division is foreshadowed in 

 the split in the daughter chromosomes. The parts which are 

 separating are not quite the same, while the line of division in 

 them indicates that the next mitosis will divide them into exactly 

 similar parts. All this, then, is evidence that in the first matura- 



JOURNAL OF MORPHOLOGY, VOL. 28, NO. 2 



