Plate IX. 



Arabic numerals placed between every two sections indicate the number 



of sections that intervene between those two (exclusive). 

 Certain uiarks on the left of each section are for the identification of the 

 sections and do not concern the reader. 



Series XI. a-0. — Sections through an embryo of Clemmys jajwnica with about 13 

 mesoblastic somites, taken out 8 days after deposition. Surface view 

 like Fig. 15 (PI. II), For detailed description see p. 60. CCx 2. 



(XXXXITI ®) 



