REPORT OF THE SOCIETY 13 



Instinct and Intelligence. 



It is customary to classify behavior actions into instinctive and in- 

 telligent. Among the lower animals actions are predominantly instinctive, 

 while in the higher animals intelligence counts for more than instinct. 

 A difficulty arises, however, in defining instinct and in determining its 

 origin. Some authorities believe that instinct cannot be separated from 

 intelligence, that it represents "lapsed intelligence" inasmuch as it is the 

 inherited result of experiences which showed first as habits and later as in- 

 stinct. This view was held by Spencer, Haeckel, Wundt, and others, but 

 under the influence of Weismannism it has been to a large extent abandoned, 

 and other views have been put forward. Some regard instinctive actions 

 as a series of reflexes linked together, " whereby certain hereditary disposi- 

 tions of awareness of certain things are linked with hereditary dispositions 

 to follow a certain routine." Loeb, Bohn and others believe that instincts 

 are tropisms or a combination of tropisms. They maintain that instinctive 

 behaviour is determined by the mechanical reaction of the organism to 

 such stimuli as light, heat, moisture, etc. Many interesting observa- 

 tions on tropic reactions of insects have been recorded in recent years, 

 and the study of reflexes and reflex actions has been raised to a higher 

 level than formerly. 



Tropisms. 



For some time it has been known that plants show tropistic move- 

 ments with regard to light, heat, gravity, moisture, contact, etc. Moreover, 

 some progress has been made towards an understanding of the processes. 

 Plants, for example, bend toward the light because the cells on the side 

 away from the light grow faster than those on the side next the light. There 

 is no conscious control of the movement by the plant. Animals, too, exhibit 

 movements under the influence of tropic stimuli. In the case of insects, 

 butterflies, bees, house flies, and many moths and caterpillars are positively 

 phototropic, and move towards the light, while maggots, bed bugs and 

 cockroaches move away from the light. 



Again, most moths move away from sunlight but move towards a lesser 

 light such as electric or oil lamps. Davenport explains this difference by 

 saying that "butterflies are attuned to a high intensity of light, moths 

 to a low intensity." Loeb explains the circling of moths and other insects 

 about a light. The stimulus orients the insect by its more intense action on 

 the muscles next the light, and the insect then moves towards the light. 



Loeb states that caterpillars of the Brown Tail Moth as they emerge 

 from hibernation in spring are positively phototropic, but after they have 



