564 



JACQUES LOEB AND MARY M. CHAMBERLAIN 

 TABLE 2 



water in the watch glass rose shghtly during observation. This 

 error made itself felt in that in the case of low temperatures the 

 actual temperature was occasionally a trifle higher than intended. 

 We shall come back to this point later on. 



When the eggs had been put into the watch glass, a field witH 

 no less than 80 and often as many as 150 eggs was selected, 

 and every minute the number of eggs which undenvent cell divi- 

 sion was counted until the last egg had divided. Very often a 

 small percentage of the eggs had remained unfertilized and these 

 of course did not divide. ^ In table 3 we give a few examples of 

 the actual measurements of the latitude of variation in the 

 time required from the segmentation of the first to that of the 

 last egg in a field. 



As far as the irregularities in the first two minutes are con- 

 cerned, they must probably be attributed to the fact that the 

 entrance of the spermatozoa into the eggs occurred somewhat 

 irregularly, the moment of insemination differing in various eggs 

 within one or two minutes. Table 4 gives the latitude of varia- 



*When this number was great the material could not be used since in such 

 cases the spermatozoa no longer entered the eggs simultaneously. 



