440 WALTER S. HUNTER 



A similar experimental analysis of other cases of instruction and 

 imitation would probably lead to similar results. (2) In dis- 

 cussing the relation of protective coloration to habitat, the 

 author presents the view that the liveries have been evolved 

 to fit the instincts which keep the animals within their peculiar 

 environments. The familiar contrast between the tiger and the 

 lion is a case in point. Inasmuch as the young lion shows traces 

 of a spotted livery, it is to be inferred that at one time the lion 

 wore a striped coat. The evolution to a stage of self -color has 

 followed a change of habitat. Certainly the reverse should be 

 considered, viz., that the instincts may have been forced into 

 alignment with the changes in coloration by the powers of 

 natural selection. (3) The present volume contains a very 

 valuable collection of observations upon instincts. The experi- 

 mental behaviorists may well take these into account in govern- 

 ing the conditions of their experimentation not only upon in- 

 stinct itself, but upon discrimination and the ' higher ' types 

 of behavior. 



The volume on the Courtship of Animals draws data from the 

 life-histories of man, the apes, other mammals, birds, reptiles, 

 amphibia, the fishes and insects. The large array of facts defy 

 either summary or review. It must suffice to state the central 

 theoretical problem of the book, the relation of structure and 

 behavior to the theory of sexual selection. The Darwinian 

 theory, in a modified form, is upheld. The brilliant colors and 

 other secondary sexual characters are not to be viewed as the 

 result of sexual selection but as the result of the stimulating 

 activities of " hormones " or juices from the thyroid, pituitary, 

 suprarenal and primary sexual glands. True behavior insight 

 is manifested in regarding the mere activities of posture and 

 display, rather than the type and degree of coloration, as the 

 essential excitant for the female, inasmuch as many somber 

 hued individuals perform the same preliminary antics. The 

 displays and postures also are not to be regarded as the result 

 of sexual selection but are to be viewed as the result of the 

 hormones. The antics of courtship serve to arouse sexual excite- 

 ment to the proper pitch in the female who then abandons her- 

 self to the more exciting performer. All force must be laid 

 upon the more intense " mate-hunger ' of the male and his 

 desire for the gratification of the impulse. 



