104 CHARLES PACKARD 



mal. This condition can hardly be interpreted as a first and 

 second polar division combined, since it occurs much earlier than 

 the normal time for the latter. The distribution of the chromo- 

 somes shows also that the two lower asters do not represent the 

 second spindle. The sperm is still exterior. Figure 17 is more 

 normal, having but two asters. The spindle has not revolved, as 

 it should have done at this time. The normal figures are at the 

 telophase of the first polar spindle. The asters are of normal size 

 and appearance, and the chromosomes show no abnormality of any 

 sort. It is curious that they have taken up a position outside of 

 the spindle, more or less in the place which they should occupy if 

 the spindle had revolved. 



There are many other abnormalities in the formation of the 

 spindle, but the examples given are typical. In practically no 

 case in which the spindle forms do the chromosomes show any 

 abnormality. 



The second polar spindle may be entirely suppressed or may 

 develop abnormally in several respects. When the first polar 

 body is not extruded, the second also may fail to be given off. 

 Figure 18 shows what is evidently a second maturation. The egg 

 was killed eighty minutes after insemination, at a time when the 

 control eggs had already extruded the second polar body, and 

 possessed a well developed egg nucleus. The spindles are normal 

 in general appearance, but abnormally small, and placed in the 

 center of the egg. If is difficult to say what would be the future 

 history of such an egg. Evidently the polar bodies will not be 

 extruded. Figure 19 shows a similar case except that the spindles 

 are larger. It will be noticed that one of the sperm asters has 

 formed before the revolution of the sperm head and cone, an 

 unusual occurrence. 



It is evident, then, that the injury done by the radium has 

 affected both the chromatin and the protoplasm, particularly 

 the latter. When the alveolar layer is not extruded the astral 

 systems are abnormal and consequently the chromosomes. In 

 such cases it is difficult to say how far the chromatin has been 

 injured. 



