LARVAE OF ARBACIA PUNCTULATA 



337 



TABLE 3 

 Constants, Experiment 1. Solution c 



f Right anal. 

 „, , Left anal. . 



2^ ^^^^"•^ ] Right oral. 



1 Left oral. . . 



48 liours 



72 hours 



96 hours 



Right anal. 

 Left anal. . 

 Right oral. 

 Left oral. . . 



Right anal. 

 Left anal. . 

 Right oral. 

 Left oral. . . 



Right anal. 

 Left anal. . 



1 Right oral. 

 [Left oral. . 



11.05 ± 0.21 



11.06 ± 0.22 



11.05 ± 0.21 



11.06 ± 0.22 



48.86 

 48.77 

 38.08 

 38.08 



57.18 

 57.18 

 43.74 

 43.62 



60.93 

 60.86 

 49.09 

 49.86 



0.33 

 0.32 

 0.24 

 0.24 



0.26 

 0.27 

 0.24 

 0.24 



0.25 

 0.25 

 0.24 

 0.23 



STANDARD 

 DEVIATION 



3.25 

 3.27 

 3.25 

 3.27 



4.91 

 4.87 

 3.65 

 3.67 



0.15 

 0.15 

 0.15 

 0.15 



0.23 

 0.23 

 0.17 

 0.17 



3.98 ± 0.19 



4.07 ± 0.19 



3.61 ± 0.17 



3.64 =t 0.17 



3.76 

 3.83 

 3.57 

 3.50 



0.17 

 0.18 

 0.17 

 0.16 



COEFFICIENT OF 

 VARIATION 



29.47 

 29.62 

 29.47 

 29.62 



10.05 

 9.99 

 9.60 

 9.64 



6.97 

 7.13 

 8.25 

 8.36 



1.52 

 1.53 

 1.52 

 1.53 



0.48 

 0.48 

 0.46 

 0.46 



0.33 

 0.34 

 0.39 

 0.40 



6.17 ± 0.29 



6.30 ± 0.30 



7.28 ± 0.34 



7.02 ^ 0.33 



Y -f > 



Figs. 1 to 22 Experiment 1. Sea-water diluted with distilled water. 

 Fig. 1 la, 24 hrs. Control. 



Fig. 2 16, 24 hrs. Size increased above the control. 



Fig. 3 Ic, figure 4 Id, figure 5 le, figure 6 1/, 24 hrs. Gradual inhibition in 

 size, otherwise normal. 



The next experiment in this series was made the following 

 summer to determine more closely the limits within which in- 

 crease of size could be obtained by dilution of the sea-water, 

 and also the effects which increased concentration would pro- 

 duce upon the developing embryo. Moreover, previous ex- 



