296 Cardiff: Synapsis and reduction 



In concluding it may be advisable to compare the results ob- 

 tained with those reported from other recent work. Gregory 

 ('04) reports a presynaptic longitudinal fission ; similar results 

 have been reported by others. One is tempted to ask, what can 

 be the significance of this ? Why should the chromatin threads 

 split and then fuse again in a close synaptic knot ? Whatever the 

 behavior of the chromatin may prove to be, it is undoubtedly a 

 purely physical process, and like many other natural phenomena 

 that have been explained, will turn out to be a much more simple 

 process than was previously expected. 



Likewise the results of Farmer and Moore, Schaffner and others 

 present many mechanical difficulties and — without in the least 

 questioning the accuracy of the work done by these investigators 

 would indicate that we are still very far from a solution of the 

 reduction problem. Thus one is obliged to think of the paternal 

 and maternal chromosomes having arranged themselves alternately 

 in a spireme previous to synapsis, a process presenting some dif- 

 ficulties. Then, if the union of paternal and maternal chromo- 

 somes takes place at the outer ends of the loops, that is, in those 

 portions of the thread farthest from the knot, this is the synaptic 

 point, and the knot in which the opposite ends of the loops are col- 

 lected is not a true synapsis — that is, a fusing together of pa- 

 rental chromatin. In other words, the contraction stage is still 

 unexplained. The same may be said of cases where an end-to- 

 end fusion of chromosomes is reported as occurring in the telo- 

 phase of the last spermatogonial and oogonial (or archesporial) 

 division. It is quite conceivable that some of the chromosomes 

 of unusual behavior reported in animals by Montgomery and 

 Wilson might conjugate much earlier than the synaptic stage, as 

 they have been shown to do much later, but if there is a general 

 conjugation of the chromosomes with the inception of the mother- 

 cell the contraction stage still remains unexplained. That a 

 tightly coiled and contracted condition of the spireme is a condi- 

 tion conducive to splitting is highly improbable from a physical 

 standpoint. 



On the other hand, if the results obtained by Allen, Berghs, 

 and those given in the present work prove to be the general con- 

 dition the contraction stage is a true synapsis. It is a region, or 



