LARVAE OF ARBACIA PUNCTULATA 



335 



TABLE 1 

 Constants, Experiment 1. Solution a {control) 



A comparison of the growth-curve of the control individuals 

 of this experiment with that of A, Plot 1, shows a much more 

 rapid development in this culture during the early stages than 

 was that of the general average for that period. Compared 

 with the total average of the controls (D), they were of about 

 the same length at the close of the first 24 hours; they then 

 developed more slowly, and, through a proportionately greater 

 growth the fourth day, attained a size 71.25, only slightly less 

 than that of the general average, 78.68. 



It may be noted that the specimens in culture h were larger 

 throughout the entire period than were those of culture a; 

 those of c, d and e were smaller. In /, the skeletons were 

 present at 24 hours only as minute centers which at the close 

 of the next day had not differentiated beyond the tri-radiate 



