524 INDEX 



Pineal, 

 tumour(s), 

 eye signs, 436 

 focal signs, 435 

 general signs, 439 

 local signs, 438 

 operation, 458, 459, 463 

 operative technique, 441 

 pathology, 430 

 photograph of patient, 455 

 pressure effects, 433 

 radio-sensitivity, 465 

 relations of, 411 

 sections of, 460, 462 

 section of brain showing, 450, 461 

 symptomatology, 435 

 Pinealectomy, 421 

 negative results, 424 

 positive results, 422 

 Pinealoma(ta), 430, 431, 433, 452, 458 

 Pineoblastomata, 431 

 Pisces, pineal system of, 200 

 Pit formation, 367 

 Placode(s), 

 branchial, 10 



division of optic placodes, 363 

 fusion of optic placodes, 369 

 ocellar, 375 

 olfactory, 10 

 optic, 10, 369 

 otic, 10 



paired sensory, 470 

 retinal, 359 

 Planar ia, 353 

 eyes of, 25 



head differentiation, 37 

 Platecarpus coryphceus, 284 

 Platydactylus, 252 

 Platydactylus muralis, 269 

 Platyhelminthes, eyes of, 84 

 Platypus, 46 

 Plesiosauria, 267 

 Plexus, choroid, 410, 415, 416 

 Plexus, 



choroid, calcification of, 412 

 choroideus superior, 184 

 marginal, 318 

 PI eur acanthus, 201 

 Plica umbra, 277 

 Poison gland of scorpion, 132 

 Polychane worms, 97 



variation in numbers of ocelli, 100 

 Polynoid, paired ocelli of, 100 

 Polyodon folium, 73 



imperforate parietal canal of, 209 

 Polyophthalmos, 97 

 Polyphagia, 438 

 Polyphemus, single eye of, 27 

 Polypteras bichir, 216, 336 

 Polyuria, 438 

 Polyzoa, 91 

 Porthetis spinosus, 343 

 Posterior, 



commissure, 417 

 diverticulum, 307, 308 

 intercalary plate, 293 



Postmedian (postorbital) plate, 472 

 Postorbital plate, 470, 471, 472 

 Post-retinal layer, 368 



condensation of, 368, 374 



of median eyes of Scorpio, 370 



pigmentation of, 374 

 Post-velar arch, 293, 468 

 Potamilla, branchial eyes of, 99 

 Prawn, retinulae of compound eye, 52 

 Precocious mental development, 425 

 Precocious sexual development, 425, 431 

 Precocity, as a result of pinealectomy, 422 

 Predominance, racial, 472 

 Pre-retina, of median eyes of scorpion, 



370 

 Preretinal 



layer of eye of Acilius larva, 120 

 of median eye of scorpion, 368 



mesodermal membrane, 368 

 Pretrochal region, of Veliger larva, 150 

 Prochordata, nervous system of, 177 

 Processes, club-shaped, 317 

 Processus brachialis, 472 

 Procolophon, 237, 270, 

 Prosauria, 267 

 Prostomium, 



situation of eyes upon, 97, 100 



variation in number of eyes on, 100 

 Proteus atiguineus, 74, 224, 225, 239 

 Protocerebrum, relation of ocelli to, 112 

 Protochordata, 168 

 Protopterus, 221, 335 



pineal organ of, 223 

 Protostraca, 136, 348 

 Prototheria, 323 

 Protriton, 237 

 Pseudo-epithelium, 433 

 Pseudopus palasii, 244, 248, 270 

 Pteraspidomorphi, 344 

 Pteraspis, 378 



monmouthensis, 474 



rostrata, 474 

 Pterichthys, 467, 472 

 Pterolepis, 331, 347 

 Pterygotus, 359, 472 

 Ptosis, 461 

 Ptycodera, 177, 179 

 Pubertas prcecox, absence of, 452 

 Pubic hair, premature growth of, 439 

 Pulvinar, 419 

 Pupil(s), 61, 164, 452 



dilated, 449 



loss of accommodation, 449 



loss of reaction to light, 449 

 Pyrosoma, 177 

 Python, 268 

 Pythonomorpha, 284, 285 



Rabbit embryo, 303, 305 



Radiograph^, 452, 456, 458 



Raja clavata, 



anterior position of end-vesicle, 210 

 heart-shaped end-vesicle of, 207 



Rana esculenta, 56, 230 



