46 The Ohio Naturalist. [Vol. VII, No. 3, 



at others on the side where there is the least cytoplasm (Figs. 3 

 and 4). There is again no uniformity in this respect. 



The variety of types of synizesis might be much increased 

 but the examples given will make it plain that there is nothing 

 uniform in the behavior of the chromatin in synizesis either with 

 respect to the nucleolus or the nuclear cavity. Synizesis appears 

 to be an artifact when considered from the standpoint of plas- 

 molysis, but the question must be settled, if possible, through 

 the study of living material. But if staining reagents are em- 

 ployed, great precautions are necessar}" even with living material. 

 At the present stage of the subject it seems useless to continue 

 the investigations by merely giving conclusions from a set of 

 preparations which may present a supposed series of uniform 

 conditions. 



The results of this investigation may be briefly summarized 

 as follows: The synizetic knot is not always around or in contact 

 with the nucleolus but very commonly one inay hnd it entirely 

 distinct from the nucleolus. The chromatin is not always uni- 

 lateral but very often central. If the knot is at one side it has 

 no evident relation to the direction of gravity. Synizesis also 

 does not mark the stage where the chromatin threads become 

 homogeneous. In cases like Liliitm tigrinum the chromatin 

 granules, if properly stained, are seen at their best after the great- 

 est possibility for contraction is passed. It seems from an inves- 

 tigation of the literature of the subject that there has been much 

 speculation and reporting on "uniform conditions" simply be- 

 cause synizesis or "synapsis" has not been explained. But it is 

 at present more important to discover the actual condition of 

 things. The time at which synizesis occurs has not shown any 

 uniformity. When one examines figures of this condition he is 

 surprised at the lack of uniformity present. Some have even 

 gone so far as to describe two "synapsis" stages before the for- 

 mation of the mother star. During the early stages of division 

 the nucleus is the seat of great chemical activity and the expan- 

 sion of the nuclear cavity and changes in the chromatin network 

 give rise to conditions which are especially favorable for the pro- 

 duction of artifacts. 



After the chromatin thread becomes thicker the contrac- 

 tions, as one would expect, are less common though by no means 

 entirely lacking. Later when the orientation of the bivalent 

 chromosomes begins, distortions are again abundant in many 

 preparations. These series of distortions and contractions in- 

 cluded under the term "synizesis" have at present no meaning 

 and the mechanics of the process remains unexplained from the 

 standpoint of a natural stage of karyokinesis. 



