142 Transplantation of the Lips of the Blastopore 
Fie. 1. Outline of blastopore region showing pieces transplanted from the 
dorsal and lateral lip. 
Fie. 2. Experiment ta,. Piece of the dorsal lip of the blastopore (see 
(1) Fig. 1) transplanted into the otic region of an older embryo, the tail of 
which is beginning to show. Embryo killed 7 days after the operation. Sec- 
tion through otic region showing piece of nervous system (2) with central 
canal and marginal layer, chorda (c) and large muscle fiber mass (m). 
x 100 diameters. 
Fic. 3. Experiment ta,;. Section through abortive neural tube, from piece 
(3) Fig. 1. X 200 diameters. 
Fic. 4. Experiment ta,. Section through chorda and brain from trans- 
planted piece (4) Fig. 1. X 100 diameters. 
Fic. 5. Experiment te,. c, chorda; m, m, muscle; n, neural tube. X 50 
diameters. 
