554 P. W. WHITING 



arrangement as shown in the succeeding figures. In figure 16 

 this process is not completed, and the chromosomes are more 

 irregularly bent. Figure 20 shows a typical case in which the 

 rods are comparatively straight. The ends of pairs b and c 

 are somewhat bent outward as if they were repelled from the 

 other pair. There seems to be considerable tension on the 

 middles of the chromosomes which are beginning to divide. 



Whether this be the explanation of the assumption of the 

 parallel arrangement of the chromosomes or not, it nevertheless 

 remains true that this position assures the middles getting as 

 near the center of the plate as possible while the chromosomes 

 are stiff and lie in one plane. 



H. PSETJDOSYNAPSIS, SYNAPSIS, AND HEREDITY 



The term 'Synaptic Phase' was first used by Moore ('95) who 

 speaks (p. 284) of "the Rest of Transformation (Synaptic Phase) 

 between the First and Second Spermatogenetic Periods." He 

 states (p. 276), "the cellular generations of spermato- or ovo- 

 genesis before and after the numerical reduction of the chromo- 

 somes will be distinguished as those of the first and second 

 spermato- or ovo-genetic series." Under the heading "the Rest 

 of Transformation" (p. 284) Moore considers the entire period 

 from the last spermatogonial division to the formation of the 

 tetrads. "The nuclear threadwork again grows coarser and 

 thicker, displaying at the same time a peculiar tendency to con- 

 tract to one side of the nucleus, leaving a great clear space 

 across which stretch numerous linin filaments. The contraction 

 is not so marked when the cells have been preserved with osmic 

 acid, nor on the outside of sections which have been preserved 

 with Flemming's fluid, where the osmium has acted directly upon 

 the cells." "Whether it exists in nature or not, the cells display 

 at this period, and at no other, a remarkable tendency to have 

 their chromatin contracted in consequence of some internal 

 change which renders these nuclear figures diagnostic of the 

 particular period in question." 



It is obvious then that Moore questions the normality of the 

 contraction, nor does he consider the contraction the essential or 



