NATURAL HISTORY OF AMERICAN LOBSTER. 151 
Page, 
Chapter VI. Anatomy of the lobster, with embryological and physiological notes — Continued. 
Sense organs 232 
Eyes 232 
Sensory hairs 234 
Relation of setae to hatching and to molting 235 
Touch, taste, and smell 236 
Balancing organs or statocysts 238 
Muscles 241 
Blood and organs of circulation 242 
Heart 243 
Pericardial sinus 243 
Arteries 244 
Arterial supply of the swimmerets 245 
Gills 246 
Branchial cavity and respiration 247 
Course of the blood in the gill 248 
Alimentary tract 249 
Grinding stomach 249 
Liver 251 
Kidneys or green glands 252 
VII. The great forceps, or big claws 253 
The crustacean claw 253 
The great chelipeds 254 
Lock hinges of big claws 255 
Asymmetry in the big claws of the lobster 256 
Torsion of the limb 257 
Breaking plane and interlock 259 
The toothed claw or lock forceps, and its periodic teeth 260 
The cracker, or crushing claw 264 
Development of the great forceps 266 
Variation in position of the great forceps 274 
Symmetry in the big claws 275 
Changes in the toothed claw at molting 278 
VIII. Defensive mutilation and regeneration 281 
Autotomy or reflex amputation 281 
Restoration of lost parts 283 
Monstrosities 285 
IX. Reproduction 288 
Sexual distinctions 288 
The ripe ovary .. ' 289 
Development of the ovary to the first sexual period 290 
Cyclical changes in the ovary after the first sexual period 291 
Disturbances in cyclical changes in the ovary 292 
Period of adult life or sexual maturity 293 
Limits of the breeding season 294 
Frequency of spawning 295 
Number of eggs produced 298 
Breeding habits and behavior in crayfish 300 
Pairing habits in the lobster 302 
Preparation for egg laying: Cleaning brushes of the lobster 303 
Egg laying 305 
