INDEX. 



Abiogenesis, 166, 195 



Achromatin, 80 



^Ethiopian region, the, 215 



Agassiz. Louis, 25 



Albertus Magnus, 10 



Aldrovandus, 16 



Alecithal egg, 185 



Alternation of generations, 172,196 



Ambulacral system of echinoderms, 



M5 



Amoeba proteus, 75 



Amoeboid movement, 75, 145 



Amphigony, 168, 170 



Amphioxus, 89 



Analogous organs, 157 



Analogy, 16, 120 



Anal glands, 128 



Anatomy, general, 68 



Anatomists of classic antiquity, 13 



Angle-worm, hermaphroditism of, 

 141; sexual organs of, 141 



Animal and plant, 207; distinction 

 between, 207; on a morphologi- 

 cal basis, 209; on a physiological 

 basis, 208 



Animal geography, 49, 211 ; organs, 

 121 



Animal pole, the, 177 



Animals, their relation to one an- 

 other, 198 



Annelids, 22 



Antimeres, 163 



Aorta, 134 



Aquatic animals, distribution of. 

 216; change in fauna conditioned 

 by depth, 216; distribution of 

 fresh-water forms, 217 



Aqueous humor, 156 



Aristotle, 7; his knowledge of the 

 subject. 7-8; his writings, 7; his 

 systemization, 8 



Archaeopteryx, 40 



Archegony, 166 



Archenteron, 124, 125, 187, 197 



Arctic and Antarctic provinces, 215 



Arteries, 132 



Articulata, 22 



Artificial selection, 52 



Arthropoda, 22 



Ascaris, 83, 98 



Asexual reproduction, 168, 171 



Assimilation, 75, 77; defined, 122; 



in animals, 122; different organs 



of, 122 

 Auditory nerve, 151; organs, 153; 



history of, 151: ossicle, 151; pit, 



152; vesicle, 151 

 Auricle, 133 

 Australia, fauna of, 50 

 Australian region, 213 



Baer, C. E. von, 41 



Beetle imitating a wasp, 59 



" Bible of Nature," the, 15 



Biogenesis, the law of, 41 



Biology, 68 



Blastoderm, 187 



Blastopore, 187 



Blastula, 187, 197 



Blood, 87, 118; arterial, 135; ve- 

 nous, 135 



" Blood " of invertebrates, 107-108 



Blood-cells, 105-106; -corpuscles, 

 106; -fluid, 105; -plasma, 105; re- 

 lations of plasma to corpuscles, 

 108; -serum, 105; red, 106; -vas- 

 cular systems, closed and lacu- 

 nar, 135; -vessels, 133 



Bone, 102, 103; composition of, 

 104; -corpuscle, 105; cross-sec- 

 tion of, 104; dried, 105; formation 

 of, 105 



Brachiopoda, 22 



Brain, 147 



Breeding, factors of evolution in, 



53 



Bryozoa, 22 

 tsuccal cavity, 127 

 Budding. 168, 169, 196; lateral, 



169; multiple, 169; terminal, 169; 



219 



