CONTENTS. xv 



SECTION V. 



Digestive System in Invertebrates* 



Arthropods. 



Insects. — Mouth parts of, 331. Of beetle, 332. Of grasshopper 

 serial homology of these parts, 333. Mouth parts of butterfly, 334. 

 Of bee, 335. Digestive apparatus of beetle, 336. Crustacea, mouth 

 parts of, 337. 



Mollusca. — Digestive apparatus of, acephala, 338. Gastropoda, 339. 

 Radula, cephalopoda, 340. 



Echinoderms. — Masticating apparatus of echinus, 341. 



Calenterata. — Medusa, 342. Lasso cells, 343. Polyps, structure, 

 344. Modes of digestion, protozoa, infusoria, 345. Rhizopods, 346. 



CHAPTER III. 



BLOOD SYSTEM. 



SECTION I. 



The Blood. 



1. Globules. — Red globules, 347. Structure of, 348. White glob- 

 ules (leucocytes), blood plates, 349. 



2. Plasma. — Coagulation of blood, 350. Functions of Blood : Of 

 plasma, of red globules, 351 ; of leucocytes, 352. 



Origin of Blood. — (1) Of plasma, (2) of leucocytes, 352. (3) Of red 

 globules, 353. 



Comparative Moiphology of Blood. — (1) Mammalian blood, charac- 

 teristic of, (2) oviparous vertebrate blood, characteristic of, 354. (3) 

 Higher invertebrate blood, characteristic of, (4) ccelenterate blood, 

 (5) protozoa. Embryonic development of blood, 356. 



SECTION II. 

 Respiratory Organs of Vertebrates. 



Lungs vs. gills. Lungs of man, 358. Structure, 359. Mechanics of 

 breathing, diaphragm, 361. Relation of pleura to lungs, 362. Costal 

 respiration, 363. Diaphragmatic or abdominal respiration, 364. Cough- 

 ing, laughing, etc., 365. 



Comparative Morphology of Vertebrate Respiration.— Mammals, 

 birds, reptiles, 366. Tortoise, amphibians, 367. Gill respiration, fishes, 

 teleosts, 368. Mechanics of gill-breathing, 369. Variation in gills of 

 fishes, sharks, lampreys, 370. Classification of fishes by respiratory or- 

 gans, 372. Transition from gill breathing to lung breathing, 373- 

 Classification of amphibians, 374. 



