TO THE EMBRYOLOGY OF AMPHIBIA. 67 



more or less curved to right and left in a wavy manner. 

 Dorsal ex-ovate as before. Ventral ex-ovate unfortunately 

 detached and lost without trace. But a mass of yolk has 

 exuded anew from the closing point of the blastopore, pro- 

 bably at the time, the ventral ex-ovate was detached. 



lu the normal course of development, the dorsal lip ought 

 to have stopped when it reached the first ex-ovate formed by 

 puncturing. But in this egg there was formed unexpectedly a 

 second ex-ovate which stood in the way of the ventral lip growing- 

 over the yolk. Accordingly the dorsal lip went on growing toward 

 the ventral lip, until the blastopore finally closed at or near the 

 second ex-ovate. The embryo was thus formed as in Fig. 88. 

 Seeing that all these disturbances took place, it is no wonder that 

 the embryo body is somewhat abnormal. 



Egg No. 2. 



Punctured at the point intermediate between the dorsal 

 lip and the yolk-pole, on the blastopore meridian. (Therefore 

 lower and more in the middle line than in the eggs of the 

 corresponding number in Groups I., and IV.). Although exuda- 

 tion at the moment was slight, the pressure of the somewhat 

 blunt needle must have been rather strong. At any rate a 

 number of larger and smaller unexpected ex-ovates appeared 

 below the dorsal lip and near the puncture-point. Afterwards 

 there were further exudations at this point as well as from 

 the left limb of the dorsal blastopore lip when it had grown 

 down some distance, showing that the arrangement of the 

 internal contents must have been considerably disturbed. The 

 results of all these were that the dorsal, ventral and lateral, 

 lips were all hindered in their growth and the embryo was 

 abnormal, being shorter, and the neural groove and folds 

 being incomplete, especially near the head-end. The closure 

 of the blastopore was also incomplete, a large yolk-plug 

 being present at the end of the third day. But in the main, 



