xiv INSTANCES OF THE WONDER OF LIFE 



PAGE 



rats, rat-fleas, and plague Bacilli 364 



yellow fever and the Stegomyia mosquito .... 365 



the importance of the white heron ..... 366 



the fate of the passenger pigeon ..... 366 



the correlation of organisms in the web of life . . 368 



the various curves of life ...... 373 



the development of the egg ...... 375 



development of a fraction of an egg .... 378 



many embryos from one egg ...... 379 



the ripening of the egg 381 



the fertilization of the egg 382 



artificial parthenogenesis ....... 383 



a remarkable case of hybridization ..... 389 



the development of nerve-fibres ..... 390 



the distinctiveness of organic growth .... 398 



internal secretions in relation to growth .... 399 



organisms of unlimited growth ...... 401 



structural registration of growth ..... 402 



regulation of growth ....... 404 



the meaning of youth ....... 408 



the play of animals . . . ' . . . .408 



courtship among animals ....... 410 



combats of males ........ 412 



significance of courtship-behaviour ..... 415 



habits of sea-lions 416 



fragrance of butterflies . . . . . . .416 



audible signalling on the part of a male moth . . .417 



post-matrimonial cannibalism ...... 419 



parental care 420 



paternal care ......... 422 



the remarkable behaviour of the bee-hunter . . . 425 



habits of dung -rolling beetles 426 



brooding insects ........ 427 



over two thousand feathers from the nest of the long-tailed tit 427 



the tabula rasa of the young bird's brain . . . 430 



the chain of parental instincts .- . . . . 431 



the prevalence of other-regarding activities . . . 433 



longevity of animals ....... 435 



a centenarian tortoise ....... 436 



the different kinds of death . 439 



