404 



GRACE MEDES 



lar and abnormal, they are of approximately equal size. Figures 

 129, 130 and 131 are from culture /. Figure 129 represents a 

 specimen below the average size, but it is regular and about like 

 that of a normal individual 36 hours old. In figure 130 the actual 

 length of the skeleton is very little greater but the form more 

 nearly approaches that of a true pluteus. It is still more irregu- 

 lar than any of the preceding and has a small accessory spicule 

 in the right side. In figure 131, skeletal structures are present 

 but while they are large and massive, they have not passed be- 



«=/ 121 



Figs. 117 to 142. Experiment 20. CO, 



Fig. 117 20a, 

 Fig. 118 20d, 

 Fig. 119 20e, 

 Fig. 120 20/, 

 Fig. 121 20/, 

 Fig. 122 20a. 

 Fig. 123 206, 



the same size as 

 Fig. 124 20c, 

 Fig. 125 20f;, 



on the right side 



24 hrs. 

 24 hrs. 

 24 hrs. 

 24 hrs. 

 24 hrs. 

 48 hrs. 

 48 hrs. 

 control. 

 48 hrs. 

 48 hrs. 



Control. 



Three skeletal centers of about normal size. 



Four centers. Size approximately normal. 



Four centers. 



Five centers. Reduction in size. 



Control. 



Skeleton somewhat heavier and less regular. 



About 



Same characters more pronounced. 



Specimen less symmetrical. Accessory spicule present 



