Lateral muscle mass of principal embryo 

 Pelvic fin ,, ,, 



Note-chord ,, ,, 



Spinal cord ,, 



Intestine 



Head-kidney of embryo A 

 Brain tissue ,, 



Pectoral fin (left) 

 Oesophagus , , 



Air-duct ,, 



The common yolk mass 

 Right pectoral fin of embryo K 

 Oesophagus 



Head-kidney 



Liver tissue ,, 



Spinal cord 



Medulla 

 Otocysts 



Pectoral fin (left) 



KH;. i 



while the v.\ 



obii([Ue!y t!n 



;_;ll (hi: hill.- 



three oilmen: 



those of A fin 



the oesophagus, an- 



pneumatic ducts. In .)' 



develop' 



principal embryo the section paw 



distance behind' this organ. C" 



are given under Fig. 94. ( x 10.) 



FIG. 98. Transvi i 



to the sami- 



jjure, but a 



inbryo 

 ' tissue 

 Mile II 

 ntricle 

 ies of ./ ,unl 

 n ducts, air-sacs, 

 iiic tissue belong- 



. 



A pelvic fin of the 

 principal embryo comes into the section 

 on its : 'i her references are given 



Lateral muscle mass of principal embryo 

 Spinal cord ,, ,, 



Notochord ,, 



Wolftian 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-sac ,, 



Wolftian ducts ,, 



- Spinal cord ,, 

 ,. Medulla 



Stomach of embryo A 



Air-sac ,, 



Medulla 



Left pectoral fin of embryo A 



Lateral muscle mass of principal embryo 

 Spinal cord ,, ,, 



Notochord ,, . 



Aorta > i 



Wolffian body 



Intestine ,, ,, 



Common yolk mass 



Intestine of embryo A 

 B 



Commencement of the portion of intestine 

 common to A and B 



Bodies of A and B uniting 



Flu. 99. Transverse section from same 

 as the last two figures, but a con- 

 siderable distance further back. The 

 , of the two defrctivr embryos are 

 are seen to be 



made up 01 - 'he 



spinal cords beii 'sable. 



The intotin.il on e embryos 



part seen towards 



uddle lieing the commencement of 

 .union terminal (wrtion. References 

 undiT tig. 94. ( x 17.) 



J. F. G. 



PI, XXIII. 



xxin 



