Materials for the Study of Variation Treated with Especial Regard to Discontinuity in the Origin of Species

Local Races, evidence as to, not a direct contribution to Study of Variation, 17 Locusts, variation in colour of tibia2, 44 Loligo, variations in segmentation of Lucanns cervus, extra antennary branch, 2 cases, 549 ; extra branch on mandible, 2 cases, 552; capreolus, ditto, 552 Luidia ciliaris, variation of pedicellarias, Lumbo-sacral plexus, 138 Lumbriconereis, imperfect segmentation, Lunibriciihis, double tail, 565 Lumbricufi, undifferentiatecl segments in, 32 ; imperfect segmentation, 156 ; spiral segmentation, 157 ; repetition of ovaries, 160; asymmetrical arrangement of organs, 160, 161 ; variation of genital openings, 162 ; duplicity,

Lye ana icarus, extra wing, 284 Lycalopex group of Foxes, frequency of LIJCHS, double (?) antenna, 551 Lynx, teeth, 224 Lysimachia, Meristic variation in flower MdCdcits cynomologus, syndactylism, 356 iniiux, spinal nerves, 137, 139 teeth, 204 rddidtua, doubtful extra molars, Maciopodidas, teeth, 259 Macrorhinus leoninus, teeth, 243 Madreporites, repetition of, 440 Maid squinado, extra index, 542 Major Symmetry, 21, 87 Mdldchins iiiurgiiii'llus, extra antennae,

transposition of viscera, 559 uterus, double, Darwin's comment Mauus, variations in, compared with those of pes, 405 ; as a system of Minor Symmetry, 403 Marsupialia, teeth, 246 — 258 Mastiff, teeth, 210, 221 ; hallux permitted in, 401 Maternal impressions and extra legs in M>Tistic Repetition, 20; kinshiji of pait- >'> repeated, 20 : similar Variation of parts in, 27, Mlii. 101; compared with asexual reproduction, 34 Meristie Variation, distinguished from Substantive Vaiiation. 2'-' : compand with 1 Imiici "tic Variation, 84

Metacarpals, development of lateral, in Aitiodactyla in correlation with syndactylism of metucarpals III and IV, Metameric Segmentation, not distinguishable from other forms of Repetnioii, 2*; enors derived from such distinction, '•'<" Meta-ternal plates, division of, 45(5 Metazoa, comparison with Protozoa, 35 M, trina fii>itr<ii-tn*. extra legs, 503 Middle Line, division by images in. 404, M/niil rnjiitn, bulldog-headed. •"•- Mule, rarity of digital variation in. 3HO :

i, extra wing, 284 Substantive and Meristic Variation in, 23; colourvariation, !'• Narwhal, development of tusks, 465 Xaxitlix, teeth, 2<il Natural Selection, chief objection to theory of, 5 ; misrepresentations of the theory, 80; difficulty in connexion with regeneration, 420 Xavvxuma, extra antennae, 521 Xcbrin, double (?) antenna, 550: <ii/llfnhaUi, double (?) maxillary palp, h.'.l N< etarine, discontinuous variation in. relation to limbs, 143 Neural canal, division of, 451 Neuration of wings varying with eye-

Oligochseta, axial duplicity, 503 ; generative organs, 159; segmentation, Ommatophoca rosaii, premolars, 237 Onitia bison, division of pronotum, 455 Operculum, double in Diicciinim, 457 Ophiacantha <nioin<il(i, normally 0 arms, not known to divide, 433 Oplddctis, fission, 433 Uphibulits, double monster, 561 Ophidia, vertebrae, 103, 123 (tyhidiuster cribrarius, fission, 433 Ophiocoina pitmild, young with 6 arms, adults with 5 arms, 433 Oplriothcld isidicula, fission, 433 Ophiuroidea, variation iniiumber of arms,

Pachydrilus sphagnetorum, dimorphic in respect of position of generative openings, 165, 168 Painted Lady butterfly, colour-variation, Palaornis torquatus, colour-variation, 43 Palamntcus burncengis, division of poisonspine, 457 Paliiiurnx ijenicillatun, eye developed as Patella, extra tentacle and eye, 279 Pattern, universal presence of, in organisms, 19-21 ; difficulties arising from. Peacock butterfly, repetition of eyespots in, 26 ; variation of, 299 Pecora, polydactylism, 37-5 Pec ten, double eyes, 280 Pedicellarise, Meristic Vaiiation of, 429 Pelamis bicolor, imperfect division of

of radial joints, 4-rayed specimens, dubiits, dumorticri, jurenxin, subsitlcatus, 436 6-rayed specimens, Penthina salicclla, extra wing, 285 Peranielidas, digits of pes, 313 Periciueta, variation in number of spermathecee, I65;forbesi, liili/midorti, 165 Pericrocotus flammeus, colour-variation, premolars, 250 oniatus, first premolar tworooted as variation. 254 iir.s(/i».s, first premolar normally two-rooted, 254 Pigments, definite variations proper to certain. 43; nature of j'ellow, in Pierida\ is.

]H>sed hybrid with Herring, 275 riliiiiiiiit.'i. not altered by Entoniscians, fiitmitix, ^yndactylism in, 356 i*, axial duplicity. "i(il Plaice, symmetrical spotting of blind riant, compared to the body of Man, 29 rinti/(-< m* niniliiiiili's, extra legs, 507 Platyonychus, not altered by Entoniscians. 9"> Platysomatichthys, 471 I'lnu-oiKi-i,:*, pigmentation of blind side, Horned, colour-variation, 47 Pora nia, 4-rayed specimen, 440; irregular division of an arm, 440 Portunion, change in Ctircinus produced

displacement and other variations, Simiti, 201 PRIONUS, supposed development of elytra as legs, coriariiiK, 148 variation in number of antennary joints, imbriconiis, 411, /noiicvrnis, 412 from blue, 44 Eenal arteries, 277 Repetition of Parts, association of these Eeptilia, vertebrae, 103, 123 Reversion, hypothesis made in order to escape recognition of Discontinuity in Variation, 76 Carcinus and other Crabs, 95 St Bernard dog, duplicity of hallux in,

of Crustacea to changes in, 100 Salmo fario, salar, truttn, 58 Salmon, bulldog-headed variety , 58 ; axial Salnuiciiui, double tail, 564 Salt lakes, Crustacea of, 96, 100 Samia cecropia, extra wing, 283 Sand-canals, repetition of, in Asterias, from head, 551 Sarcophilus, teeth, 255 Sarsia, Meristic Variation in, 424 ; with six segments, 424 ; with five segments, 276; of Snakes, 276 Scarites pyracmon, extra legs, 500 Scheme, shewing the relations of parts in

Secondary Symmetry, 481 Scolopendra, number of segments, 94 Scorpion, double poison-spine, 457 ; Scraptia fusca, extra antenna?, 523 Seals, variations in dentition, 235 Segmentation, metameric, not in kind distinct from other forms of Repetition, 28 ; two ways by which a full segmentation may have been achieved in phylogenv, .analogy with Discontinuous Variation, r,i; 3i .iial characters, statistics as to, in Sorr.r, miked varietv, 51; Spaniel, teeth, 221 Species, the problem of, 2. Methods of

Discontinuity of, a fact, 2 Specific Din'eime.-, indefinite, 2 Sperinathecic of Earthworms, variation Stability, Organic, 36 Starfishes, theory of origin of repetition in, 29; variations in number of ray-. 439; multiplication by fission, 433 Stcntor, duplicity. ">('.ii .stirhiijiitx, arrangement of tube-feet Stomobrachium octocostatinn, variety having tentacles in double series, StniniiuUa, double (?) antenna, atrn. Swan, cervical vertebrae, 33; colourvariation of voung, 44 ; Inachial plexus, 130

a relation between optical images, 19 almost universal presence of in living organisms, 21 of mamma-, 191 in dental Variation, 267 indigital Variation, Man. 324,402; C it, 314; in manus and pes, 4u3 in nuclear division, 430; in variations in segmentation of ovum, Bilateral, characters of, 88; as appearing in variations of flatfishes, 467 Symmetry, Secondary, preliminary account, 475; principles, Scheme of relations of parts in, 481 ; parts repeated in, <ieometricallij peripheral to points of origin, 557; relation to Primary,

Tadpole, extra spiracle in, 465 Timid ccenurus, transposition of generative organs, 170 ; case of six suckers and segments prismatic, 565 t'lliptica, asymmetrical arrangement of genital pores, 170 xa<iinat<i, "intercalated" segments, 169; repetition of generative organs in proglottides, 169 ; two genital pores at the same level, 170; consecutive genital pores on same side, 170; bifurcation of chain, 566 xulium, changes in position and alternate arrangement of genital pores, 170 tenuicullix, bifurcation of chain,

Tarsus, in some beetles with only four joints appearing, 25 ; variation in number of joints, Jilatta, 63, 415; various numbers of joints in families of Orthoptera, 415 Taurliina nirens, extra legs, 509 Ta.riden, teeth, '233 Tit. rug baccata, colour-variation, 47 Teal, Gargauey, division of digits, 392 Teeth, in undifferentiated series not credited with individuality, 32 numerical Variation, 195 ; division of, 268; duplicate, 268; statistics of Variation, 200,

Telephone, colourvariation, lividus, 43 division of pronotum, nigriextra legs, nisticus, 502 '• Telescope " Gold-fish, 453 Tell ina, sinistral variety, 54 Tenebrio granarius, double (?) leg, 548 Tentacles of Molluscs united, Helix liixpida, 461; Limaxaijreatis, 460 repeated, Patella viilgata, 279 bifid, P1iysa acuta, 280 of Holothurians, 435 Tenthredo solitaria, extra legs, 502 if/nobilis, extra leg, 546 Terias, colour-variation, 52, 53 ; anemone, hecabe, mandariiia, maricsii, 52 ; betheseba, constantia,jaegeri, 53 Terminal members of Series, variation

and 3-rayed varieties, 437 Tetrops pncusta, double (?) leg, 545 Thoracopagous twins, transposition in, Thumb, variation in number of phalanges, 324 double, 349 Thylacimts, teeth, 255 Tin/Incite* pilosits, double (?) antenna, Thyonidium, variation in number of organs, 435 Tiarops poludiademata, specific character Tomato, colour-variation, 47 Tonicia, variation in colour of scutes, Tongue, division of, 451 Toxotits, extra eye, 280 Transposition of viscera, 560 Triasters, symmetry of, 430; found in bilaterally symmetrical areas of segmenting ovum, 464 Trichoilex at/i-iucus, double (?) leg, 547 Tricliosurus vulpccuhi, premolars, 254

Tulip, Meristic Variation in, 00 Turliot, pigmentation oflower side, 407, Twins, homologous, 559; Simultaneous Variation of. as a case of Bi- lateral Symmetry, 559 Siamese, peculiarities of, 500 ; thoracopagous, 560 in Kchinod.-rms and in Aniphi- Ulnar nerve, variations in composition of, 13(5 ; a second. 333 Uterus, double, Darwin's comment on, 77 ; is a case of median division, 451 Vertebra? , Meristic Variation in, 102 imperfect division, 103, l'>^ Homieotic Variation, 106 reduction in numbers, Man,

coloured like male in island of, 254 Wall butterfly, variation in ocelli and Water-pore, extra, in Jlijiiiuiiirin, 460 Webs, between toes of Duck, absent, 401 Weevils, four visible joints in tarsus, 25 Wing, supposed to replace a leg in Z//- Wings, supernumerary in Insects, 281 fore and hind, varying simultaneously in Lepidoptera, 2'.i3 quills of, varying with quills of tail in Pigeons, 309 Woodpecker, Green, colour-variation, 43 viscera in, 560 Xylntrupc.i ,ji,l,nn, variation of horns in.

tion in dorsal fin, 471 Zaiinliri.-i quadripunctata, double (?) an- CAMBRIDGE : 1'RINTED BY C. J. CLAY, M.A. AND SONS, AT THE UNIVERSITY PRESS. HENRY B. ORR, Ph.D., Professor at the Tulane University of Louisiana. Crown 8vo. 6s. net. SCOTSMAN. — 'Professor Orr does not profess to have proved, or worked out in its detail, his new "Theory of Development and Heredity." But he has stated it with admirable perspicuity, and the solution which he offers of the problem, " How are changes brought about in the structure of organisms, and how are these changes transmitted to succeeding generations? " deserves thoughtful examination as offering a key to certain of the deeper secrets of life and growth, both bodily and mental.'

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