OBSERVATIONAL LESSON XX 



PART I 



A DEVELOPING TADPOLE (continued, 2nd Investigation) 



PREPARATIONS FOR WORK 



The frog's spawn will now be about fourteen days old. 



FIGURE 162. A Tadpole just hatched.* 



DIRECTIONS TO THE PUPIL 



(1) Repeat your observations 

 on the developing eggs and 

 make drawings as before. 



FIGURE 163. A Tadpole underside showing 

 gills and mouth 3 days after hatching. 



* Two days after reaching the stage shown in figure 157. 



