467 



TABLE XI. 



Systematic Survey showing the derivation of the germ-layers of the Amphioxns 



from the parent-cell (cytula), and of the main organs from the germ-layers. 



(Tree showing the ontogenetic descent of the cells in the Amphioxns). 125 



Medullary tube 

 Tubus medullaris 



Outer ski 

 Epidermit 



Flesh-mass 

 Jttusculi 



Notochord 

 Chorda 



Canales Gill-epithelium 

 tangueferi Epith, branchiate 



Leather skin 

 Corium 



Primitive 

 kidneys 



Pro- 

 tonephra 



Testes Ovaries 

 Testiculi Ovaria, 



Parietal 

 Coelom- 



thelium 



Skin-sensory 



layer 



(Lamina neurodermalis') (L 

 (Fig. 157, As) 



Skin-fibrous 

 layer 



Intestinal-fibrous Intestinal-glan- 

 layer dular layer 



nina inodermalis') (Lamina inogastralis') (lamina myxogastralis) 

 (F,g. 157, lif) (Fig. 157, dj) ^ ,~ ?~ 9 ,~ > 



(Fig. 157, dd) 



Y 



Exoderma (Fig. 155, e) 

 (Skin-layer, or outef germ-layer) 



Entoderma (Fig. 155, i) 

 (Intestinal layer, or inner germ-layer) 



Gastrula FFig. 22, J, K ~\ 



(Cup-germ) j_Fig. 155, p. 444 J 



llastula (Fig. 22, F, G) 

 ">r-genn) 



n Morula (Fig. 22, E) 

 (Mulberry-germ) 



Monerula (Fig. 22, A) 

 (Parent-cytod) 



