Nov., 1912.] The Reduction Division in Fuchsia. 3 



In his paper on Oenothera lata x O. lamarckiana (5) he finds 

 starch grains present in the cytoplasm of the mother cell. These 

 grains become more abundant until the reduction takes place 

 after which they are not found. He finds what he calls "pro- 

 chromosomes", but in a later paper considers these bodies to be 

 nucleoH. The presynaptic stages show a continuous spirem 

 which is exceedingly delicate and coiled. Then follows the con- 

 traction, after which follows a stage in which the spirem is much 

 shortened and several times thicker than just before the contrac- 

 tion. He does not believe that the nucleoli break up and move 

 out into the cytoplasm waiting to be re-collected into a new 

 nucleolus in the new nucleus, as Schaffner believes to be the case 

 in Lilium philadelphicum. There are twelve chromosomes and 

 one or two "heterochromosomes", or as he calls them in a later 

 paper — nucleoli. He believes O. lamarckiana to be a pure strain 

 and not a hybrid. 



In the paper on Oenothera gigas (8) Gates says "The absence 

 or partial absence of a close pairing of chromosomes in diakinesis 

 and on the heterotyptic spindle is in strong contrast to the con- 

 dition in other genera of plants where the chromosomes are 

 regularly paired. However * * * similar failure to pair is 

 often exhibited. These cases appear to be the exceptions to the 

 general law enunciated by Montgomery in 1901 from his observa- 

 tions on Hemiptera, that homologous chromosomes of maternal 

 and paternal origin pair with each other in synapsis. Later 

 observations on a variety of forms, in which there are morpholog- 

 ical chromosome differences, show that ordinarily chromosomes of 

 similar size and shape pair with each other and justify the view of 

 Montgomery which has been widely adopted. There is some 

 variety in the size and shape of the chromosomes but nothing 

 constant was observed." In the anaphase the longitudinal split 

 generally described does not always show. There are some 

 irregularities in the reduction such as an unequal number of chro- 

 mosomes passing to the two poles. 



Davis in his first paper on Oenothera (2) observes the nucleus 

 filled with a close reticulum having the chromatin material dis- 

 tributed around the periphery of the nucleus. Next follows the 

 appearance of extremely delicate strands connecting the bodies, 

 forming an open net work. These strands readily thicken and 

 become more numerous until finally the nucleus is filled with a 

 relatively close reticulum. During this time the chromatin 

 bodies become smaller and seem to contribute their material to 

 formation of the strands so that the only large structures in the 

 nuclei are the nucleoli. Synapsis, as he calls the synizetic con- 

 traction, begins slowly and finally carries the strands away from 

 the nuclear wall. During this contraction there is a marked 

 change in the structure of the reticulum At first the reticulum 



