Plate Vin. 



Arabic nuQierals placed between every two sections indicate the number 



of sections that intervene between those two (exclusive). 



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



sections and do not concern the reader. 



Series X. a-n. — Sections tlivougli an embryo of Chniimys japonica witli about 10 

 mesoblastic somites, talcen out 6^ days after deposition. For detailed 

 description, see p. 57. C'C'x2. (LI ffl) 



(The numeral between k and I should be -i instead of 5.) 

 Series X. lon^, — Posterior portion of a longitudinal section tlirongli an embryo of 

 Tiinnyx jdpnnicus, taken out from the same deposit at the same time as 

 that of Series X. CC'x 2. (LI long) 



Epibl. = Epiblast. Mesnbl. = Mesoblast. 



Hijpohl. = Hypoblast. Mednll. Canal. = Medullary canal. 



The lines e-k denote the planes through which the transverse sections 

 marked by the same letters pass through. 

 Series XII. lon^. — -Posterior portion of a longitudinal section through an embryo of 

 Trioiii/.c jajioiiiaiis, taken out from the same deposit at the same time as 

 that of Series XII, (PI. VI). C't'x 2. (157 loug) 



J})iii=zAimnon h. r. = Bloodvessels. 



cV/.':=Extra-embryonic cœlomic cavity, i/k. =rz Yolk. 



