370 INDEX-GLOSSARY. 



D 



Danger signal, 268. 



Danube, 349. 



Dart-sac, 131. 



Darwin, 58. 



Death, 10, 11. 



De Candolle, 4. 



Decidua, 338. 



Deer, 355. 



Delamination Formation of epiblast and hypoblast, by division of the 



segmented ovum parallel to the surface. 



Dentine The part of a tooth or scale developed from the dermis, 155. 

 Dermal Belonging to the dermis, or, in general, to the skin, 34. 

 Dermis The deeper part of the skin derived from mesoderm, 76, 90, 138, 



178, 227, 231. 

 Deutomerite, 17, 18. 

 Development Direct d., 107; Indirect d. = Metamorphosis, q.v. ; of 



nervous system, 150 ; of feather, 231 ; of hair, 270 ; Hydra, 26 ; 



Distoma, 35 ; Tsenia, 43 ; Ascaris, 53 ; Lumbricus, 67 ; Hirudo, 82 ; 



Astacus, 107 ; Anodonta, Unio, 121 ; Amphioxus, 147 ; Scyllium, 167 ; 



Rana, 222; Columba, 256; Lepus, 305; Homo, 338; Comparison 



of, 317. 



Diaphragm, (1) in the Frog The muscular anterior boundary of the body- 

 cavity, 191 ; (2) in Mammalia A muscular and tendinous partition 



separating the thoracic and abdominal cavities, 294. 

 Diastema (Sictrrqua, an interval) A gap between the incisor and pre- 



molar teeth, 284, 329, 338. 



Diastole, in the heart The relaxation which follows each contraction, 97. 

 Didelphia ($/-, two ; t&Qv;, the womb), 346. 

 Differentiation Morphological d., 20. 

 Digestion. See Nutrition. 

 Digestive System Vorticella, 13 ; Hydra, 27 ; Distoma, 29, 36 (embryo), 



38 (cercaria) ; Teenia, 41 ; Ascaris, 48 ; Lumbricus, 55 ; Hirudo, 76 ; 



Astacus, 192; Anodonta, Unio, 113; Helix, 125; Amphioxus, 139; 



Scyllium, 160 ; Rana, 189 ; Columba, 241 ; Eana, 282 ; Homo, 329 ; 



Comparison of, 313. 



Digit, 176, 186, 239, 241, 281, 282, 327, 329. 

 Dimorphism (Bis, doubly ; noptyf], a shape) The occurrence of bi-sexual 



and uni-sexual forms in the life cycle of one animal, 73. 

 Dinornis, 347. 



Diploblastica (SnrXows, double ; /SXao-n/cos, growing), 340. 

 Dipnoi, 153, 350. 



