578 FERN AND us PAYNE 



paired at synapsis. These authors beheved that an end to end 

 pairing took place, but so far as I can see they have no convincing- 

 evidence for such a conchision. Much of our work on the ques- 

 tion of the reductional and equational divisions is worse than 

 worthless, because of the fact that writers have not considered 

 the question of synapsis. It has been shown by Wilson and 

 others that one pair of chromosomes may divide one way while 

 another pair is dividing another way. How then, can we be 

 sure of reductional and equational divisions without having 

 traced the stages in synapsis and in the formation and division 

 of the spermatocyte chromosomes? A second chromosome 

 is shown in plate 1, figure 25, and the various stages of bending 

 into a ring in figures 26 to 30. It is interesting that the rod and 

 the ring in this case show no indication of the future division. 

 A third chromosome in which I have given a more complete 

 series of stages of bending is shown in plate 2, figure 1. The 

 stages of transformation are given in figures 2 to 10. Later stages 

 in the transformation of this ring could not be followed. A 

 fourth chromosome which is rather remarkable in having an 

 identification mark is shown in plate 2, figure 19. This is the 

 large chromosome in this figure and its j^eculiar characteristic 

 is the presence of two more or less oval bodies at the division 

 point. In the prophases these bodies usually stain more intensel}- 

 than the rest of the chromosome. Just what they mean, if any- 

 thing, I do not know. In late stages of condensation they are 

 lost to view. By means of these bodies, which are present in 

 this chromosome and so far as I have been able to make out in 

 no others, the chromosome can be easily followed in its trans- 

 formation. Sometimes it is joined end to end with another 

 chromosome (plate 2 figure 20). Another interesting fact in 

 connection with this chromosome is that it may form a typical 

 ring by bending (plate 2, figs. 21-25) or it may occasionally 

 condense into a bivalent without passing through the ring stage 

 (plate 2, figures 26 and 27). Three small chromosomes are 

 recognizable in the late prophases. These are shown in plate 

 2, figure 11. They also may form a ring (12 and 13) or may 

 condense into the bivalent without ring formation (14 and 15). 



