f. Normentafeln zur Entwicklungsgeschichte der Wirbeltiere. 



There are some minor changes, the Hght band is broader and better defined, and extensions of pigment 

 over the yolk have been so uneven that a number of irregulär oval areas are left unpigmented, causing a 

 mottled appearance in this region. 



Fig. 35. (X 5-) 



Side view of larva 126 days old, length 39 mm. The young Nedurus now conforms in outline to 

 the adult. In color hovvever it is decidedly diiferent. 



Introduction to Tables. 



The material upon which the normal tables are based was collected in 1903. At the time the 

 illustrations were made from the living material, several specimens of the same stages were fixed in various 

 Solutions. Among these 10 7o formalin caused the least distortion. This formalin -fixed material proved 

 most satisfactory for work not involving cytological study. The material was stained in toto with haemato- 

 xylin, imbedded in paraffin and counterstained on the slide with weak picric acid, orange G or eosin. 

 Unless otherwise stated the above fixation and staining have been used. Each of the stages designated in 

 the following tables was sectioned in transverse, horizontal and sagittal planes. Besides these series many 

 others have been consulted in which the material was fixed and stained by other methods. The total 

 number of series at our disposal was upwards of 250. 



