566 



JACQUES LOEB AND MARY M. CHAMBERLAIN 



TABLE 1 

 Differences in minutes between segmentation of first and last egg in a field at 



were liable to be too short when the outside temperature was 

 very high. Thus the value 13 minutes for the temperature of 

 13° is unquestionably too low, and probably the values 46 and 

 47 for 9°C. are also too low. At the higher temperatures the 

 values differ much less, since the temperatures approximate much 

 more the room temperature. 



We are now in a position to compare the expected with the 

 observed result. The expected result is the series of tempera- 

 ture coefficients for the time from insemination to the time when 

 the first egg of the set begins to divide; the observed result is 

 the series of temperature coefficients for the latitude of variation, 

 i.e., the time which elapses between the segmentation of the first 

 and last egg in a set. These two sets of coefficients should be 

 identical and table 5 shows the degree of agreement. 



A comparison shows that the temperature coefficients for the 

 latitude of variation are practically identical with the tempera- 

 ture coefficients for cell division, and that where a noticeable 

 difference exists it is always in the same direction, namely, the 

 coefficients for the latitude of variation are a trifle too small. 

 We can account for this on the basis of the deficiency in the 

 method we have already discussed, namely that when the tem- 

 perature of observation was low and that of the room high, the 



