( 4^7 ) 



TABLE XI, 



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

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



(Tree showing the ontogenetic descent of the cells in the Amphioxus). 185 



Medullary tube 

 Tubus medullaris 



-organs 

 Scnsuaria 



Outer skin 

 Epidermis 



Flesh-mass 

 Musculi 



Notochord 

 Chorda, 



Blood-vessels 



Canales GUI-epithelium 

 tangueferi Epith, branchiate 



Leather skin 

 Corium 



Primitive 

 kidneys 



Pro- 

 tonephra 



Testes Ovaries 

 Testiculi Ovaria 



Parietal 

 Coelom- 



Epi- 

 thelium 



larium 



Visceral 

 Coelom- 



Epi- 

 thelium 

 Endocce- 

 larium 



Intestinal 

 muscle 

 wall 

 Peri- 

 en terum 



Mesen- 

 tery 

 Mesen- 

 terium 

 I 



Stomach 

 epithelium 



Liver 

 epi- 

 thelium 



Small 

 intestine 



epi- 

 thelium 



Epithelium 

 digestivum 



Skin-sensory Skin-fibrous 



layer layer 



, I/imina neurodermalis) (Lamina inodermalis) 



(Fig. 157, hs) (Fig. 157, hf) 



Intestinal-fibrous Intestinal-glan- 



layer dular layer 



(Lamina inogastralis) ( Lamina myxogastralif\ 

 (Fig. 157, df) (Fig. 157, dd) 



Exoderma (Fig. 155, e) 

 (Sklu-layer, or outer germ-layer) 



Ento^erma (Fig. 155, i) 

 (Intestinal layer, or inner germ-layer) 



Gastrula f~Fig. 22, j,k ~\ 

 (Cup-germ) [_Fig. 155, p. 444 J 



JBlastula (Fig. 22, f, G) 

 a) 



(Bladder-germ) 



Morula (Fig. 22, E) 

 (Mulberry-germ) 



Oytl 



_„tula (Fig. 22, B) 

 (Parent-cell) 



Monerula(Fig.aa,4) 



(Pare * 



rent-cytod) 



(1) 



