6 The Ohio Naturalist [Vol. XIII, No. 1, 



nuclear sap containing the mass of chromatin which has been left 

 to one side. No evidence whatever was found to show that any 

 contraction of the chromatin had taken place. The enlargement 

 of the nuclear cavity and the consequent withdrawal of the 

 membrane away from the chromatin gives the appearance of a 

 contraction, but actual measurements failed to show any diminu- 

 tion in chromatin area. 



During this stage definite changes take place in the nature of 

 the chromatin threads as the spirem becomes differentiated. 



This view is somewhat similar to that expressed by Schaffner 

 in Synapsis and Synizesis (21) although he believes that synizesis 

 is a true shrinking of chromatin material due to the effect of the 

 killing fluid on the nuclear contents, which has become loosened 

 from the nuclear wall on account of the swelling of the nucleus. 

 One important proof for this conclusion was the fact that in many 

 instances there are symmetrical contractions showing the same 

 peculiarities as in ordinary plasmolysis. On the other hand 

 Gates and Davis whom I have quoted above believe this stage to 

 be natural and do not believe it to be an artifact. They base 

 their opinion on the fact that the contraction is of such constant 

 occurrence in all forms studied. 



Because of the apparently pecidiar process of chromosome 

 formation reported for the Oenotheras differing somewhat from 

 both the type of division held by Allen and others on the one hand 

 and by Schaffner and others on the other, it seemed desirable to 

 the writer to investigate the fonnation of the chromosomes in 

 Fuchsia. Accordingly a study of the reduction division in the 

 microsporocytes of Fuchsia was taken up under the direction of 

 Professor John H. Schaffner, whose help and kindly criticisms have 

 been of inestimable value throughout the whole year's work. 



When starting the problem I expected to find the chromo- 

 somes formed in the manner described by Gates for Oenothera 

 rubrinerves and by Davis for Oenothera biennis. The most of 

 my attention was directed toward finding how the chromosomes 

 were formed. I wished to see whether it was by the thickening 

 of the spirem followed by a transverse division by which the 2x 

 number of chromosomes were differentiated and then cut off in 

 pairs, which should afterward fold together to form the bivalents; 

 or whether the spirem thickened and then folded and twisted 

 around into the number of loops before a subsequent separation 

 into the reduced number of chromosomes. These two methods 

 are very similar in results but somewhat different in detail. Gates 

 found the chromosomes formed in the first way described and 

 since Fuchsia is not so distantly related to Oenothera, it was 

 natural to expect to see the chromosome formation brought about 

 in much the same way that Gates found in Oenothera. 



