Lateral muscle mass of principal embryo 

 Pelvic fin ,, ,, 



Notochord ,, ,» ' 



Spinal cord „ ,, ' 



Intestine „ M - 



Head-kidney of embryo •/ 



Brain tissue ,, -^ "^ 



Pectoral fin (left) ,, ~'\\.- 



Oesophagus ,, " 



Air-duct ,, 



The common yolk mass - 



Right pectoral fin of embryo B ,i|-^\ , 



Oesophagus ,, - . 



Head-kidney „ 



Liver tissue ., "(y-r 



Spinal cord ,, i 



Medulla ,. 



OtOCySts „ 



Pectoral fin (left) 





Lateral muscle mas ; of prim pal < mbryo 

 Spinal cord 



...Notochord 

 Wolffian ducts 



Intestine ,, ,, 



Common yolk mass 



Left pelvic fin of principal embryo 



Hepatic tissue of embryo B 



Hepatic tissue of embryo A 

 Stomach of embryo B 

 Air- ,, 



Wolffian ducts ,, 



-■ Spinal cord ,, 

 Medulla 



Stomach of embryo .-/ 



Air-sac , , 



Medulla 



Left pectoral fin of embryo A 



Lateral muscle mass of principal embryo 

 Spinal cord „ „ 



) J. \ ""~' — // 



Aorta ,, ...-_ ....(....., W i I 



Wolffian body ,, ,, .- \' " /}T>) 

 Intestine ,, ,, \. j \5-/" 



Common yolk mass -i" > ~'~ 



Intestine of embryo A (j Wy^"^) ''""v- 



...... (i yC\ ; , 



Commencement of the portion of intestine / t/'"|V 7 \-r , ^ // 



common to A and B I ( ' " "I \v - 



Bodies of 7 and B uml \ / 





j. r. o. 



XXIll 



