SOME SILKWORM MOTH REFLEXES. 153 



female from which they are taken, the males always neglect the 

 near-by live female and go directly to the scent-glands. Males 

 attracted to the isolated scent-glands remain by them persistently 

 trying to copulate with them, moving excitedly around and 

 around them and over and over them with the external genitalia 

 vainly trying to seize them. 



The behavior of males with the antenna of only one side re- 

 moved is striking. A male with left antenna off when within 

 three or four inches of a female (with protruded scent- glands) 

 becomes strongly excited and moves energetically around in re- 

 peated circles to the right, or rather in a flat spiral thus getting 

 (usually) gradually nearer and nearer the female and finally com- 

 ing into contact with her, when he is immediately controlled by 

 the contact stimulus. A male with right antenna off circles or 

 spirals to the left. It is a curious sight to see two males with 

 right and left antenna off, respectively, circling violently about 

 in opposite directions when the immobile female a few inches 

 removed protrudes her scent-glands. This behavior is quite in 

 accordance with Loeb's explanation of the forward movement of 

 bilaterally symmetrical animals. 



The results of all the experiments tried show how rigorously 

 the male moths are controlled by the scent attraction (chemo- 

 tropism) and how absolutely dependent mating (the one adult 

 performance of the males) is on this reaction. If we can find 

 specialized animals in a condition where all attractions and re- 

 pulsions (stimuli) but one are eliminated we may readily perceive 

 the rigorous control exercised by this remaining one. We are, 

 unfortunately, in the general circumstances of animal life too 

 much limited to the use of very simply organized animals for 

 reaction and reflex experimentation. This tends to make it diffi- 

 cult to carry over to the behavior of complexly organized ani- 

 mals the plrysico-chemical interpretation which is steadily gaining 

 ground as the key to the understanding of the springs and char- 

 acter of the behavior of the simplest organisms. But where the 

 complex stimuli and reactions that determine the behavior of 

 complexly organized forms can be isolated and studied the inevi- 

 tableness of much of this behavior can be recognized. 



Reflexes of Moths Without Ccpha/ic and Thoracic Ganglia. 



