Abstract
The history of chromonemata in mitosis of T. reflexa is briefly summarized an pp. 4-5. As the chromosomes spread out in telophase four chromonemata become visible instead of the two of anaphase. They pass thru interphase without anastomosing and without much dislocation; occasionally at resting stage pairs of chromonemata may be observed, their members running parallel for some distance but mostly the chromonemata run in single paths. Early prophase shows 4n chromatic tracts in each of which two chromonemata are paired, the spirals being shoved into one another closely. In spiral prophase pairs of pairs of chromonemata are arranged into a group of four and the metaphase chromosome is thus essentially established. Later prophase involves only an increase in quantity and change in PH of the matrical coatings of the chromonemata, and lateral polarization of the materials of the chromosome which is believed to be essential for the reproduction of the (invisible) gene thread. At no stage in mitosis do chromonemata entangle.
Discrepancies between the observations presented above and those of other authors is laid to two main reasons: acid fixation without proper pretreatment and the dif iiculty of interpreting refraction images.
The author is indebted to Dr. L. W. SHARP and Dr. C. L. HUSKINS for suggestions and criticism.
