364 The Ohio Naturalist. [Vol. XV, No. 1, 



many reduction preparations of apparently the same age. Miss 

 Elkins regards this "synapsis" as a natural stage in the reduction 

 division and not as an artifact as the many types of synizetic 

 masses lead the writer to beheve. The synizetic knot is not 

 necessarily found to one side of the nuclear cavity, but is often 

 in the center in which case the nucleolus is usually found to be 

 lateral in position. Often threads with numerous granules are 

 seen projecting from the greater mass of chromatin material 

 toward the periphery of the nucleus. Before the contraction 

 of the spirem, there were no double granules observed and the 

 spirem was single, but following synizesis a heavy spirem extends 

 throughout the nuclear cavit}' touching the periphery at various 

 points. (Figs 12, 13, 14). No evidence whatever in favor of 

 the theory that the double spirem is the result of the conjugation 

 of two simple spirems was found. The evidence rather points 

 to a longitudinal splitting instead of a conjugation. (Fig. 14). 



The heavy spirem which often showed very plainly its double 

 character is thrown into loops around the periphery of the nuclear 

 cavity and in an older sporocyte each incipient loop appeared 

 to have twisted more tightly together, shov.dng as definite bodies 

 still connected together so that almost the entire length of the 

 spirem may be traced by following the twists of the loops. Miss 

 Elkins described the chromosomes as being formed by the halves 

 of the double spirems constricting at inter\'als until only a very 

 slender thread united the segments, but the writer found a number 

 of preparations which showed well defined loops in which the 

 twisted condition ai:)peared plainly just at the time when they 

 were pulling apart, as seen in Figure 17. Often large granules 

 are seen upon the linin thread even after well twisted loops are 

 formed and the double character of the thread is seen even in the 

 fully formed chromosome, if one focuses carefully. 



By the transverse pulling apart of the heavy looped spirem, 

 there results rather indefinitely shaped chromosomes which are 

 joined together for some time by very delicate threads. (Figs. 

 18, H), 20, 24). The irregular masses tend to shorten and thicken 

 forming twelve rather well individualized chromosomes. (Figs. 

 21, 22, 23). In many of the preparations of this stage it is impos- 

 sible to count the chromosomes because of their proximity and 

 the irrcgularit}" of shape. 



After the chromosomes have acquired their individual shape 

 they arc still connected by fine threads (Fig. 24) and the nuclear 

 membrane becomes indistinct while the incipient spindle ap])ears 

 about it. (Figs. 24, 25). The membrane disappears and a 

 definite bipolar spindle is apparent from the beginning with the 

 chromosomes and their connecting threads arranged over it. 

 The chromosomes appear to be gradually ])nlled into an equatorial 

 position by a shortening of the connecting threads. During this 



