CONTENTS

LECTUREPAGE
XX.Regeneration[1]
XXI.Regeneration (continued)[23]
XXII.Share of the Parents in the Building up of the Offspring[37]
XXIII.Examination of the Hypothesis of the Transmissibility
of Functional Modifications		[62]
XXIV.Objections to the Thesis that Functional Modifications
are not transmitted		[80]
XXV.Germinal Selection[113]
XXVI.Germinal Selection (continued)[136]
XXVII.The Biogenetic Law[159]
XXVIII.The General Significance of Amphimixis[192]
XXIX.The General Significance of Amphimixis (continued)[210]
XXX.In-breeding, Parthenogenesis, Asexual Reproduction,
and their Consequences		[238]
XXXI.The Influences of Environment[265]
XXXII.Influence of Isolation on the Formation of Species[280]
XXXIII.Origin of the Specific Type[299]
XXXIV.Origin of the Specific Type (continued)[330]
XXXV.The Origin and the Extinction of Species[346]
XXXVI.Spontaneous Generation and Evolution: Conclusion[364]
INDEX[397]

LIST OF ILLUSTRATIONS

FIGUREPAGE
35 B (repeated).Hydra viridis, the Green Freshwater Polyp.[4]
96.A Planarian cut transversely into nine pieces[6]
97.A Planarian which has been divided into two by a longitudinal cut[14]
98.The leg of a Crab, adapted for self-mutilation or autotomy[17]
99.Regeneration of the lens in a Newt's eye[21]
100.Regeneration of Planarians[25]
101.A Starfish arm[27]
76 (repeated).Diagram of the maturation divisions of the ovum[39]
82 (repeated).Fertilization in the Lily[59]
91 (repeated).Hind-leg of a Grasshopper[83]
102.Brush and comb on the leg of a Bee[84]
103.Claw on the leg of a 'Beach-fly'[85]
104.Digging leg of the Mole-cricket[86]
105.Ovary of a fertile Queen-Ant and ovaries of a Worker[91]
106.Three Workers of the same species of Indian Ant[97]
107.A, B. Larva of a Caddis-fly[105]
107 C.Leptocephalus stage of an American Eel[133]
108.Nauplius larva of one of the lower Crustaceans[161]
109 A, B.Metamorphosis of one of the higher Crustacea, a Shrimp[162]
109 C.Second Zoæa stage[163]
109 D, E.Mysis-stage and fully-formed Shrimp[164]
70 (repeated).Daphnella[166]
110.The largest of the Daphnids (Leptodora hyalina), with summer ova
beneath the shell		[166]
111.Nauplius larva from the winter egg of Leptodora hyalina[167]
112.Development of the parasitic Crustacean Sacculina carcini[168], [242]
113.The two sexes of the parasitic Crustacean Chondracanthus gibbosus[170]
114.Zoæa-larva of a Crab[171]
115.Caterpillar of the Humming-bird Hawk-moth Macroglossa stellatarum[178]
3 (repeated).Full-grown caterpillar of the Eyed Hawk-moth[178]
4 (repeated).Full-grown caterpillar of the Eyed Hawk-moth[179]
8 (repeated).Caterpillars of the Buckthorn Hawk-moth[179]
116.Development of the eye-spots in the caterpillar of the Elephant
Hawk-moth Chærocampa elpenor		[180]
117.Caterpillar of the Bed-straw Hawk-moth Deilephila galii[181]
118.Two stages in the life-history of the Spurge Hawk-moth Deilephila euphorbiæ[182]
119.Caterpillar of the Poplar Hawk-moth Smerinthus populi[184]
120.A, Symmetrical, and B, asymmetrical curve of frequency[207]
121.Life-cycle of Coccidium lithobii[214]
122.Conjugation of a Coccidium (Adelea ovata)[216]
123.Conjugation of Coccidium proprium[218]
79 (repeated).The two maturation divisions of the 'drone eggs'[236]
124.Alternation of generations in a Gall-wasp[245]
125.The two kinds of galls formed by the species[246]
126.Ovipositor and ovum of the two generations of the same species
of Gall-wasp		[247]
127.Life-cycle of the Vine-pest (Phylloxera vastatrix[249]
128.Heterostylism[254]
38 (repeated).A fragment of a Lichen[261]
129.Aberration of Arctia caja, produced by low temperature[276]
130.Skeleton of a Greenland Whale, with the contour of the body[313]
131.Peridineæ: species of Ceratium[325]

LECTURE XX

REGENERATION

Budding and division—Every theory of regeneration in the meantime only provisional, a mere 'portmanteau theory'—Regeneration not a primary character—Volvox—Hydra—Vital affinities—Planarians—Heteromorphoses—Enemies of Hydroid-colonies—Regeneration in Plants—In Amphibians—In Earthworms—Different degrees of regenerative capacity according to the liability of the part to injury—Different results of longitudinal halving in Earthworms and in Planarians—Regeneration in Birds—The disappearance of the power of regeneration is very slow—Morgan's experiments on Hermit-crabs—Autotomy in Crustaceans and Insects—Regeneration of the lens in Triton.