TO THE EMBRYOLOGY OF AMPHIBIA. 83 



other portions of the blastopore lip have to compensate by covering 

 a larger extent. 



4). When the puncture is made on any part of the upper 

 hemisphere it has no direct effect on the closure of the blastopore 

 but may affect more or less the process of the reduction of the 

 segmentation cavity or in other words the internal re-arrangement 

 of the egg materials, and may thus indirectly cause disturbance 

 in the growth of the blastopore lip as well as in the formation 

 of the embryonic body. 



5). In most cases, the final closing point of the blastopore 

 coincides with the tail end of the future embryo. But occasionally 

 there are exceptions to this general rule. In Group II., No. ( J, 

 and Group III., No. 3, the ex-ovates were at the tail end of the 

 embryo. 



6). In accordance with the statement under the last heading, 

 the location of the embryonic body in punctured eggs is very 

 variable. Thus, in Group I., Nos. 3, 6, and 8 ; Group II., No. 8 ; 

 Group III., Nos. 3 and 6, and Group IV., Nos. 2, 3, 6, and 7, 

 the embryonic body was formed almost entirely upon the upper 

 hemisphere. But in No. o of all the groups, it was on the lower 

 yolk hemisphere. And several intermediate stages between these 

 two extremes may be seen in other eggs. The most peculiar cases 

 are the eggs No. 4 of Groups II., III., and IV., in which the 

 embryos appeared obliquely along the former equatorial zone. 



7). There is, however, a general tendency in every egg for 

 the blastopore to close .at the yolk-pole (s. sir.),, and for the 

 embryonic body to have its axis coinciding with the plane of the 

 blastoporic meridian. The former fact is evident in No. o of 

 Groups I., and II., and Group III., Nos. 7, and 0, while the 

 latter appears in Group I., No. 4 in which the curved axis of 



