INDEX 



Midgut, 



in chick, 

 48-hr., 221 

 72-hr., 226 



derivatives of, 189, 190 

 Mitosis {see Cleavage) 

 Modification of polarity, 



in Fucus, 298 



in hydroid, 233, 234 



in limb disk, 99 



in sea urchin, 33, 34 

 Modulator, 85 

 Motor nerves, 160, 161 

 Motor region, of spinal cord, 



in chick embryo, 153 



effect of limb upon, 153, 154 



in human, 211 



in pig, 271 

 Mucous gland, 134 

 Mucus, in frog embryo, 132 

 Multiple embryos, 



in amphibian, 56 



in armadillo, 37 



in sea urchin, 8 

 Muscle, from myotome, 195 

 Muscular contraction, in human, 280 

 Myelencephalon, 165, 166 



in chick, 



48-hr., 216, 218, 219 

 72-hr., 223, 224 



in pig, 271, 272 

 Myotome, 137 



of chick, 72-hr., 216 



differentiation of, 194, 195 



Nails, in human fetus, 283, 287 



Nasal pit {see also Olfactory pit), 130, 



131, 133 

 Nasal placode {see also Olfactory plac- 

 ode), 



in amphibian, 70 

 Nephrostome, 137, 138 

 Nephrotome, 



differentiation of, 194, 195 



in frog, 135 

 Nerve fibers, 



degeneration of, 145, 146 



effect on regeneration of limb, 158, 

 239, 240 



to limb, 147, 148 



orientation of, 151, 152 



origin of, 143 



325 



Nerve fibers — {Continued) 



outgrowth of, 143 



regeneration of, 145, 146 

 Nerve ganglia, 



in chick, 72-hr., 214 

 Nerve outgrowth {see Cone of growth) 

 Neural crests, 71, 137 



effect of limb on, 153, 154 



neuroblast of, 141, 142 



pigment cells from, 160, 161 



sheath cells from, 159, 160 



spinal ganglia from, 160, 161 



sympathetic ganglia from, 160, 161 

 Neural folds, 160 



in chick, 209, 210, 211 



in human, 27.5 

 Neural plate, 160 



folding of, 126, 127, 128, 129 

 Neural tube, 160 



in chick, 



48-hr., 216, 221 

 72-hr., 225, 226 

 33-hr., 213, 214 

 24-hr., 210, 211 



differentiation of, 162 



in human, 274, 275 



neuroblasts in, 141, 142 

 Neuroblasts, 



differentiation of, 143, 153, 154 



migration of, 142 



in motor region of spinal cord, 153 



of olfactory pits, 133 



origin of, 142 



relation of, to limb, 153, 154 

 Neurula, 92 



fields of, 93 



potencies of, 76 



of salamander, 76 

 Notochord, 70 



in chick, 207, 208, 211 



in embryo, 137 



formation of, 128 



in human, 269 



presumptive, 120, 121, 122, 123, 

 124 

 Nucleoproteins, in cytoplasmic inherit- 

 ance, 89 

 Nutrition, 



in chick, 201 



in mammal, 258, 276, 277 



Olfactory epithelium, 168 



