PLATE 2 



EXPLANATION OF FIGURES 



4 Amoeboid motion resulting in change of form exhibited by connective tissue 

 cells of the primitive or 'round' type. I, cells a-c, from the extreme margin; 77, 

 cells d-e, from just within the margin; and ///, cells f-g, from the interior of a 

 round cell area. I and //from the pectoral, III from the caudal fin. Numerals 

 as in the preceding figures. 



5 /, transformation of a round to a spindle cell in the pectoral fin of a Fun- 

 dulus embryo 6 mm. long, 20 days after fertilization, 11 days after hatching. 

 From 4.20 to 4.22 p.m. there was in this cell an apparently retrograde change from 

 spindle to stellate form but at 4.24 p.m. this had been proven temporary. //, 

 transition of a stellate cell to a temporary spindle form. Letters and numerals as 

 in preceding figures 



6 Apparent retrograde change from spindle to a stellate form in a cell under- 

 going rather slow locomotion. The stellate phase of such cells is nearly always 

 temporary. From the same embryo as fig. 5; cap., blood-capillary. Other letters 

 and numerals as in the preceding figures. 



144 



