TO THE EMBRYOLOGY OF AMPHIBIA. 13 



In Phyllomedusa, segmentation .seems to approach the typical 

 holoblastic mode much more closely than in other anurans, the 

 blastomeres of the upper and lower hemispheres showing less 

 difference in size. In Rhacophorus, quite the contrary is the 

 case, segmentation approximating more to the meroblastic type 

 as already stated. Again, the head of the Rhacophorus embryo 

 when raised over the general surface of the egg is not pro- 

 portionally as large as that of Phyllomedusa as figured by 

 Budgett. Also, the gills are not so enornously large in the 

 Japanese genus as in the South American. The embryo of 

 Rhacophorus as a whole is rather small in comparison with the 

 yolk-mass which remains almost always spherical in shape. 

 Moreover, the main part of the embryonic body when seen 

 in sections is wedged into the yolk along its dorsal surface. 

 On the other hand, the mode of the tail formation and the 

 shape and the formation of the mesoblastic somites, as well as 

 the rudimentary condition of the suckers, are strictly alike in 

 the two genera. 



II. 



OBSERVATIONS UPON EGGS OF RHACOPHORUS, RANA, 



AND RUFO FIXED ON THE PRISMEN-ROTATOR 



OF ZEISS. 



The Prismen-Rotator of Zeiss, as I have before stated, 

 enables one to study the upper and lower views of an egg as 

 well as the lateral view of it from any point of its circumference, 

 without once touching the egg and thus without the risk of 

 calling forth abnormalities by handling. A full description of it 



