296 



C. M. CHILD 



Fig, 41 is constructed in the same manner as fig. 40 and shows 

 the frequency of normal eyes for the pieces of different size from 

 different regions. The curves for pieces of the same size are 

 drawn in the same way in the two figures. In fig. 41 we see that the 

 frequency of normal eyes shows in general relations of the same 

 general character to the regions of the body and the size of the 

 pieces as does the frequency of head formation or whole formation. 



Comparison of fig. 41 with fig. 40 shows at once that the curves 

 of normal eyes are similar in course to the curves of head forma- 

 tion and 'wholeness,' but it is also evident that in pieces of a given 

 size and from a given region the frequency of normal eyes is 

 always less than that of wholes. In other words, under similar 

 conditions a larger piece is necessary for the formation of a whole 

 with normal eyes than for the formation of a teratopthalmic 

 whole. It is impossible to doubt after examination of these 

 curves that the factors which determine the frequency of wholes 

 as compared with headless pieces are essentially the same in 

 general character as those which determine the frequency of 

 normal as compared with abnormal eyes. 



TABLE 2 



Series Jfi and 4-1 ■ Worms 16 — 18 mm. in length, in good physiological condition. 

 Begun July 15, 1908. 



DIAGRAM ' PIECE ! TAILLESS 



NORMAL 

 WHOLES 



TERATOP- 

 THALMIC 

 WHOLES 



HEADLESS DEAD 



41 (20 pieces 

 each) 



40 (20 pieces 

 each) 



20 

 35 

 15 



