INDEX 



967 



Oxygen consumption, at fertilization, in 

 Fundulus heteroclitus, 244 

 effects of fertilization on, 240 



Oxygen supply, mechanisms for, in devel- 

 oping embryo, 903 



Oxyphil cells, of parathyroid glands, 879 



Oxytocin, 101 



P 



Pachynema chromatin conditions, 137 



Pachytene stage of meiosis, 128, 132, 137 



Pacinian corpuscle, 840, 842 



Palade, G. E., 159 



Palatal conditions, in chick, 615 



in frog, 615 



in mammal, 615 

 Palate, primary, 615 



secondary, 844 



formation of, 615, 615 

 Pancreas, a compound alveolar gland, 630 



development of rudiments of, in chick 

 embryo, 628 

 in frog embryo, 628 

 in shark embryo, 628 



endocrine aspect of, 630 



exocrine aspect of, 630 



histogenesis of, 630 

 Pancreatic acini, 625 

 Pancreatic rudiment, development of, 623, 



625 

 Pangenesis, theory of, 114, 348 

 Panniculus carnosus, 705, 722 

 Papilla, dermal, in developing feather germ 

 in chick, 574 



of hair, 581 

 Papillary cone, vascular, of reptilian eye, 



849 

 Parabronchi, of bird lung, 647 



of chick, 645 

 Parachordal cartilages, of primitive em- 

 bryonic skull, 671 

 Parallelism, 551 

 Paralutein cells, 85 

 Paraphysis, 822, 881 

 Parascaphirhynchus albus, xvii 

 Parasympathetic division, of autonomic 



nervous system, 836 

 Parasynapsis, 137 

 Parathyroid glands, 619, 879, 880 



development of, 880 



distribution of in vertebrate groups, 880 



of human embryo, 878 



role of in calcium metabolism, 879 

 Parietal cells, of stomach mucosa, 621 

 Parietal mesoderm, 506 

 Parietal organ, 881 



Parietal pericardial wall, formation of, 871 

 Parkes, A. S., 44 



Parmenter, C. L., 219 



Parotid gland, innervation of, 831 



Pars caeca retinae, of developing retina, 

 845, 853 



Pars intermedia, of pituitary gland, 877 



Pars optica retinae, of developing retina, 

 845 



Parthenogenesis, artificial, Bataillon's 

 method for producing in 

 frog, 218 

 in annelid worm, Chaetopterus, 111 

 results obtained by work on, 220 

 from non-sexual egg, 216 

 natural, 216 



Parthenogenetic merogony, 266 



Passerifonnes, xix 



Pasteels, J., 354, 355 



Pasteur, Louis (1822-1895), 57 



Path, cocopulation, of sperm during ferti- 

 lization, 248 

 initial entrance of sperm during fertili- 

 zation, 248 . 



Patten, B. M., 305, 364 



Patterson, J. T., 313, 315, 320, 383, 384 



Payne, L. F., 193 



Pecten, of bird's eye, 846, 849 



Pectoral girdle, 689 



Pelagic eggs, 251 



Peltier, 213 



Pelvic girdle, 689, 693 



Pelvis, formation of in mammal (human), 

 784 



Penetration path of sperm, 248 



Penis, bifid, in male opossum, 196 



Pepsin, secretion of, 621 



Perameles, superficial implantation in, 916 



Perch, Perca flavescens, egg membranes of, 

 165 

 sperm production in, 30 



Perforatorium of sperm, 149 



Periblast, central, 319 



Periblast, peripheral, 319 



Periblast tissue, of elasmobranch fishes, 

 321 

 origin of in teleost fishes, 324 



Pericardial cavity, 857, 861 



Pericardial division, primary, of coelom, 

 formation of, 859 



Pericardial walls, independent, develop- 

 ment of, in amphibians, 871 

 in chick, 871 

 in mammals, 872 

 in reptiles, 871 



Pericardioperitoneal canals, 861 



Perichondria! bone formation, 667 



Perichondrium, definition of, 665 



Peridental membrane, definition of, 614 



