620 



Aqueous chamber and humour, 



183 



Arachnoid fluid, 155 

 Archenteron, 579 

 Archicerebrum, 380 

 Area opaca, 583 

 Area pellucida, 583 

 Area vasculosa. 585 

 Arm, see Fore-limb 

 Arterial arches, 80, 452, 523, 599 

 Arteries : Frog, 27, 80 ; Crayfish, 



376 ; Mussel, 407 ; Dogfish, 



449 ; Rabbit, 522 ; Vertebrate 



embryo, 599, 609 

 Arthobranch, 375 

 Arthropoda, 220, 360, 386, 411 

 Articular membrane, 361, 368 

 Articular processes, see Zygapo- 



physes 



Artificial selection, 227 

 Arytenoid cartilage, 144, 517 

 Asexual generation, see Agamo- 



bium 



Asexual reproduction, see Fis- 

 sion, Budding, Spore 

 Assimilation, 149, 234, 305 

 ASTACUS, see Crayfish 

 Aster, 562 

 Astragalus, 51, 504 

 Atlas vertebra, 498 

 Atrial pore, 420 

 Atrium, 420, 421 

 Atrophy, see Vestige 

 Auditory capsule, 39, 41, 436, 



492 

 Auditory organ (incl. statocyst): 



Frog, 45, 1 86 ; Crayfish, 381 ; 



Mussel, 409 ; Dogfish, 465 ; 



Rabbit, 535 ; development of, 



in Vertebrates, 595 

 Auditory ossicles, 492, 536 

 Auricle, see Heart 

 Automatism, see Movements 

 Aves, 219, 418 

 Axial fibre : of Vorticella, 272 ; 



of Carchesium, 277 

 Axial parts, 4, 29 

 Axis fibre, see Neuraxis 

 Axis vertebra, 499 

 Axon, 167 



B 



Backbone, see Vertebral column 

 BACTERIA, 152 ; structure, 257 ; 

 nutrition, 257 ; animals or 

 plants ? 257 ; rapid multipli- 

 cation, 289 ; practical direc- 

 tions, 260 

 Basal cartilages of fins, or basalia, 



44 2 -443 



Bell of medusae, see Umbrella 



Bilateral symmetry, 296 



Bile, 68, 148 



Bile-duct, 68, 447, 516 



Bile-passages, 134 



Binomial nomenclature, 215 



Biogenesis, 288 



Biology, I 



Bird, development of, 582 et seq. 



Birds, see Aves 



Bladder, see Gall-bladder and 

 Urinary bladder 



Blastoccele, see Segmentation- 

 cavity 



Blastocyst, see Blastodcrmic 

 vesicle 



Blastoderm, 384, 470, 574, 582 

 ,, embryonic and extra- 

 embryonic portions, 

 585, 606 



Blastodermic vesicle, 586, 610 



Blastomere, 577 



Blastopore, 201, 349, 384, 579, 

 581, 582 



Blastostyle, 311, 313, 314 



Blastula, 577 



Blind spot, 183, 55(i 



Blood : Frog, 20, 78, 85, 105 ; 

 Earthworm, 336, 339 ; Cray- 

 fish, 379 ; Mussel, 408 ; / 

 let, 424 ; Dogfish, 458 ; Rabbit, 

 483, 543 



Blood-corpuscles : colourless, 

 see Leucocytes ; red, 105, 458, 

 483, 543 



Blood-sinus, see Sinus 



Blood- vessels : Frog, 80 ; Earth- 

 worm, 337 ; Crayfish, 37') ; 

 Mussel, 407 ; Lancelet, 42,) ; 

 Dogfish, .\ 1 1> ; litibbit, 520 



