INDEX AND GLOSSARY 



ACINETA, a group of protozoa, 



development of, 41. 

 Acquired characters, question 



of their inheritance, x. 

 Arnphioxus, a marine animal, 



representative of the primi- 



tive vertebrate stock, experi- 



ments on eggs of, 61. 

 Anabolism, the formation of 



more complex chemical 



bodies by the agency of pro- 



toplasm, 86. 

 Animal cells, characteristic 



mode of growth, 111. 

 Antennularia, Loeb's experi- 



ment, 117. 



Ants, polymorphism in, 125. 

 Ascidians, tunicate animals, 46. 

 Atavism, the occurrence in an 



organism of a character ab- 



normal in it, but normal in 



an ancestor, 24. 



B 



Bees, polymorphism in, 125. 

 Beetroot, grafting experiments, 



Begonia, reproduction from 

 leaves, 46. 



BERT, experiments on rats, 73. 



BERESOWSKY, skin-grafting, 75. 



BEYERINCK, upon galls, 51. 



Biophores. Each determinant, 

 according to Weismann, is 

 composed of a number of 

 ultimate living pieces, the 



biophores, which are the 

 active agents that direct the 

 functions of a mature cell, 

 ix, 22. 



Blastosphere, an early stage in 

 embryonic development ; the 

 embryo consists of a hollow 

 sphere, the walls of which 

 consist of a single layer of 

 cells, and the cavity of which 

 is called the segmentation 

 cavity, xvii ; explanation of 

 formation, 97, 98. 



Blood, transfusion of, 75. 



BLUMENBACH, nisus forma- 

 tivus, 5 ; upon galls, 50. 



Bone-grafting, 73, 74. 



Bonelfia, sexual dimorphism in, 

 122. 



Bryozoa, a group of minute 

 animals which form encrus- 

 tations on seaweeds and 

 stones, 46. 



Buds, origin of, 28 ; reproduc- 

 tion and regeneration by, 46. 



C 



Cell, description of, 31 ; charac- 

 ters possible in, 88 ; differen- 

 tiation of, in development, 

 112 ; as units in morphology 

 and physiology, 113 ; Sachs 

 on, 114; Vochtiiig on, 114, 

 116. 



Cell theory, relation of, to 

 heredity, 31. 



Centrosome, an organ of cells 



