xiv INSTANCES OF THE WONDER OF LIFE 



PAGE 



rats, rat-fleas, and plague BaoiUi ..... 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 fertihzation 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 



