TO THE EMBRYOLOGY OF AMPHIBIA. 57 



May 7, 9:16 a.m. : — (Fig. e). Blastopore completely closed ; yolk plug 

 no longer visible. Ex-ovate attached to the left side of the 

 closing point of the blastopore. Head and neural folds faintly 

 recognizable although the posterior part of the neural groove 

 is not yet distinct. 

 4:18 p.m. : — (Fig./). Embryo formed and quite normal. Ex-ovate 

 attached to the left side of the tail end. 



Here we must conclude that the blastopore was closed at the 



punctured point (i.e. at the point opposite the first dorsal lip) by 



an excessive growth of the dorsal and lateral lips : as the embryo 



was situated in front of this, it must have been formed entirely 



on the lower hemisphere as given diagrammatically in Fig. 80. 



Egg No. 6. (Figs. 72 a-g, Fig. 81). 



May 5, 1:35 p.m. : — ^Fig. a). Punctured closely below the dorsal 

 blastopore lip, slightly to the right of the median line. 

 4:17 p.m.: — (Fig. b). Nothing noteworthy. 

 May 6, 8:32 a.m.: — (Fig. c=posterior, Fig. d = \eû side view). Seg- 

 mentation-cavity and blastopore area similarly acuminated 

 toward the punctured point. 

 4:30 p.m. : — (Fig. e). Blastopore circle much smaller and now 

 circular in shape. Ex-ovate attached to its upper margin. 

 Area of the segmentation cavity entirely vanished. 

 May 7, 9:20 a.m. : — (Fig. /). Embryonic area defined. Ex-ovate 

 attached to its posterior end. Blastopore already closed. 

 4:21 p.m. : — (Fig. g). Embryonic body well formed, normal in 

 every way except that it is short. Ex-ovate attached to its 

 posterior end. 



Fig. 81 gives a diagrammatic representation of this egg. The 



embryo except for its shortness is entirely normal as is also its 



location. This is probably due to the circumstance that the 



puncture was slight, compared with Egg No. 2. Although the 



point of injury was different, the results in this egg are very 



much like those seen in Egg No. 3. 



