CONTENTS vii 



Page 



VEGETATIVE PROPAGATION AND REGENERATION IN FLAT-WORMS (PLATY- 



HELMIA) Flukes and Tapeworms. Planarian Worms Microstomum - - 329 



VEGETATIVE PROPAGATION AND REGENERATION IN BRISTLE- WORMS 



PODA) Possible Meaning of Segmentation. Regenerative Powers. Chains 

 Formed by Budding. Lateral Budding of Syllis ramosa ..... 329 



VEGETATIVE PROPAGATION AND REGENERATION IN MOSS-POLYPES (POLYZOA) 

 Formation of Colonies by Budding. External Winter-Buds, Internal Winter- 

 Buds (Statoblasts). Regenerative Powers ....... 330 



VEGETATIVE PROPAGATION AND REGENERATION IN THE HIGHER GROUPS OF 

 MANY-CELLED ANIMALS (METAZOA) Regenerative Powers of Molluscs, 

 Arthropods, and Vertebrates. Budding of Ascidians or Sea-Squirts (Urochorda) 331 



CHAPTER LIV. ANIMAL DEVELOPMENT PROPAGATION 

 BY MEANS OF EGGS 



DEVELOPMENT FROM EGGS IN ANIMALCULES (PROTOZOA) Origin of Many- 

 celled Animals (Metazoa) from Colonial Animalcules (Protozoa). Division 

 of Physiological Labour. Evolution of Tissues. Life-History of Volvox, a 

 Colonial Animalcule 333 



DEVELOPMENT OF EGGS IN MANY-CELLED ANIMALS (METAZOA) Ontogeny and 

 Phylogeny. Preformation and Epigenesis. Polar Bodies. Law of Recapitu- 

 lation. Cleavage or Segmentation of the Embryo. The Blastula. Develop- 

 ment of the Freshwater Polype (Hydra). The Gastrula, Gastraea Theory. 

 Development of a Sponge. Development of the Lancelet (Amphioxus). In- 

 fluence of Food- Yolk on Development 335 



ANIMAL LIFE-HISTORIESPROTECTION OF EGGS 

 AND YOUNG ANIMAL DWELLINGS 



CHAPTER LV. LIFE-HISTORIES, &C., OF BACKBONELESS 



ANIMALS (INVERTEBRATA) 



LIFE-HISTORIES, &c., OF ZOOPHYTES (CCELENTERATA) Alternation of Genera- 

 tions in Hydroid Zoophytes. Evolution of Jelly-Fishes (Medusae), and Stages 

 in their Degeneration. Life-History of Aurelia. Nursing of Eggs and 

 Embryos in Jelly-Fishes, Sea-Anemones, and Corals. The Planula Larva - 349 



LlFE-HlSTORlES, &C., OF HEDGEHOG-SKINNED ANIMALS (ECHINODERMATA) 



Larval Forms. Life- History of Brittle -Stars (Ophiuroidea}\ the Pluteus 

 Larva : Direct Development and Nursing of Embryos in certain Brittle-Stars 

 (e.g. Amphiura squamata). Pluteus Larva of Sea-Urchins (Echinoided}\ 

 Nursing of Embryos in Hemiaster: Burrowing Sea-Urchins. Ordinary Star- 

 Fishes (Asteroidea)\ Bipinnaria and Brachiolaria Larvae: Nursing Arrange- 

 ments in Pterasteridce and Leptoptychaster. Sea-Cucumbers (Holothuroidea) : 

 Auricularia Larva : Nursing of Embryos in Psolus ephippifer - 354 



LlFE-HlSTORIES, &C., OF SEGMENTED WORMS (ANNELIDA) Bristle-Worms 



(Chcztopoda) Care of Eggs in Scale- Worms (Polynoids), Autolytus prolifer^ 



