146 



INDEX AND GLOSSARY 



physical properties (see 

 Chromatin, Chromosomes) 

 as the bearer of heredity, 19 



NUSSBAUM, views on origin o 

 germ- cells, 17. 



Nutrition, influence of, on de- 

 velopment, 2. 



O 



OLLIER, bone-grafting, 73. 



Ontogeny, the development of 

 an individual from the egg 

 upwards, 9. 



Osteoblasts, cells which are the 

 active agents in bone-forma- 

 tion, 73. 



Ovogenesis, the formation of 

 egg-cells in the ovary, 13. 



Pangenesis, Darwin's provi- 

 sional hypothesis, that the 

 sexual cells were composed 

 of minute particles (gem- 

 mules), given off by all the 

 cells of the body, 21. 



Periosteum, a cellular sheath 

 of bones, 73. 



Physiological units, Herbert 

 Spencer's name for hypo- 

 thetical ultimate units of 

 living matter, 22. 



Pistachio, influence of tem- 

 perature on, 121. 



Plant-cells, mode of growth, 

 110. 



Plasomes, Hertwig's name for 

 theoretical units of proto- 

 plasm, 32. 



Plasticity of plant tissues, 117, 

 119, 120. 



Pluteus, a free - swimming 

 larval stage in the develop- 

 ment of echinoderms, 54. 



Podophrya, reproduction of, 41. 



Polymorphism, the appearance 

 of the same species in several 

 different forms in ants and 

 social insects, 125. 



PONFICK, on transfusion of 

 blood, 75. 



Preformation, identical with 

 the original meaning of evo- 

 lution, which see. 



Prothallus, the leaf - shaped 

 green organism that grows 

 from the spore of a fern and 

 produces sexual organs, 49. 



Pseudopodia, extensions of pro- 

 toplasm beyond the general 

 contour of the cell, 41. 



R 



Radiolaria, a group of pro- 

 tozoa, 44. 



Regeneration in plants and 

 animals, 45, 47. 



Ehipsalis grafted on Opuntia, 

 71. 



Roux, contrast between epi- 

 genesis and evolution, 6 ; 

 mosaic theory of, 56. 



Rudiment, used here as a 

 translation for the word 

 anlage, which means the 

 first plotting-out or begin- 

 ning of a living structure. 

 Darwin showed that rudi- 

 mentary organs in adult 

 creatures were for the most 

 part vestiges of organs that 

 had lost their use. In this 

 treatise ' rudiment ' is ap- 

 plied to an organ or struc- 

 ture in its incipient condi- 

 tion, whether that incipient 

 state be visible in a young 

 embryo, or a hypothetical 

 structure in the germplasm, 

 6 ; latent rudiments, 37. 



