10. 50 
10.59 
11. 04 
11.13 
11. 28 
11.37 
.0 5 .10 
I 1 . . . 1 1 ■ , I m m 
Fig. 3 Seven successive views of the end of a growing nerve fiber showing its 
change of shape and progression. The sketches were made with the aid of a 
camera lucida at the time indicated on the left. The red blood corpuscle, shown 
in outline, marks a fixed point. The observations were made upon a living 
preparation of ectoderm from the branchial region, isolated in lymph, four days 
after isolation. The total length of fiber at that time was 800/x. 
