. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. COLCHICINE AND CLEAVAGE IN ARBACIA To determine the effects of the colchicine upon the consistency ("viscosity") of the eggs, experiments were performed as follows: eggs were placed in the colchicine solution 10 minutes after fertilization and let stand 10 minutes. They \vere then centrifuged, together with controls, for the same time and at a speed just sufficient to produce a slight derangement but no extensive stratification of the control eggs. It is well known that the viscosity of the eggs varies considerably
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. COLCHICINE AND CLEAVAGE IN ARBACIA To determine the effects of the colchicine upon the consistency ("viscosity") of the eggs, experiments were performed as follows: eggs were placed in the colchicine solution 10 minutes after fertilization and let stand 10 minutes. They \vere then centrifuged, together with controls, for the same time and at a speed just sufficient to produce a slight derangement but no extensive stratification of the control eggs. It is well known that the viscosity of the eggs varies considerably at different stages in the mitotic cycle. Therefore, untreated eggs of the same lot which were fertilized 10 minutes later than the experimental series were centrifuged for the same time and at the same speed. This was done in order to obviate the possibility that any difference in consistency between the experimental and control eggs might be due to a further development of the controls because of the possible blocking of the experimental ones by the colchicine «l FIG. 1. Control eggs (left) and colchicine-trcatcd eggs (right). Both were centrifuged 20 minutes after fertilization for the same time and speed. A comparison of the stratification indicates that a lowering of the viscosity has occurred in the colchicine-treated ones. In each experiment only eggs from a single female and sperm from a single male were used. The eggs were kept in finger bowls at room temperature with the water varying from 22° to ° C. Controls were run with each experiment. Observations All experiments in which the stratification of control and colchicine- treated eggs was compared after centrifuging showed the experimental eggs to have a lower viscosity as indicated by a more marked stratifica- tion of certain of their cytoplasmic components. The hyaline zone was only barely indicated in the controls, whereas it was well developed in the colchicine-treated eggs (Fig. 1). It is to b
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
