228 



THE PHYSIOLOGY OF TWINNING 



Double monsters: interpretation 

 of, 6-8; in fishes, 51-57; in 

 worms, 29 



Duplicate twins, origin of, in 

 fishes, 46-48 



Duplicity in limbs, 193-205 



Duverney, 74 



Dwarf larvae, in Patiria, 15, 16 



Earthworms, twinning in, 28, 37 

 Echinodermata, 179-85 

 Echinus miliaris, 182-85 

 Erdwurm, Dr., 132 

 Experimental production of twins 

 in fishes, 70-72 



Falkenberg, H., 92, 93, 175-78 



Fasciola, 218 



Fisher, G. H., 125 



Fission : theory of origin of double 

 monsters in fishes, 68-70; theory 

 of twinning in armadillo, 108- 

 20; transverse, 210 



Frog twins, 92 



Fundulus heteroclitus, 61, 71, 190 



Gametic reproduction, 213, 214 

 Gastrulation, significance of, in 



twinning, 5-7, 11 

 Gemmill, J. F., 7, 39, 40, 44, 45, 



49, 50, 52-54, 56, 59-62, 64, 70, 



71, 75, 95, 168-70, 216 

 Gesell, A., 159-63 

 Giraldes, 203 

 Goldfish with double tails, 191 



Harrison, R. G., 194-200 



Harvey, W., 74 



Hazards, developmental, in hu- 

 man twins, 135-58 



Heart-dead twins, 148-54 



Heath, H., 21 



Helodriliis caliginosus trapezoides, 

 30,31 



Hemiacardia, 149 



Hemididymus, 42 



Hemihypertrophy, viii, 9, 70, 159- 



63 

 Holoacardia, 149 

 Homoeosis, 94 



Hybrid twins, in Patiria, 13, 14 

 Hyman, L. H., 63, 192 



Indeterminate cleavage, relation 

 to twinning, 3, 4 



Jablonowski, 58 



Janus monsters, 122, 124, 126 



Johnson, A., 203 



Kaestner, S., 7, 77-80, 85, 98 

 Katadidymi: in birds, 83, 84, 90; 



in starfish larvae, 19, 25; in 



trout, 42 

 Klausner, F., 39, 41 

 Kleinenberg, N., 28-30 

 Knoch, 7, 39, 42 

 Kopsch, F., 39, 42, 93; theory of 



embryo formation, 57-60 

 Korschelt, E,, 31, 32 



Lemery, 74 



LerebouUet, A., 38, 39 



Lillie, F. R., viii, 54 



Limb duplicity, causes of, 204, 205 



Liver fluke, reproduction in, 213, 



214, 219 

 Lumbricus terrestris, 30; L. trap- 



ezoides, 28 



McBride, E. W., 180, 182-84 

 Mateer ovimi, 127, 128 

 Meckel, 7, 75 

 Mediacardia, 155 

 Mesodidymus, 42 

 Metameric segmentation, 210, 217 

 Microstomum, 217 

 Miller ovum, 128 

 Mirror-imaging, 7, 164, 189 

 Monozygotic twins, vii, i 

 Monstrorum Historia, 38 



