414 C. H. TURNER 



phere saturated with ether, chloroform, or carbon dioxide, re- 

 cover at once. One by one, the appendages of eight letisimu- 

 lating individuals were removed. With two exceptions, these 

 showed no signs of recovering from the feint until several min- 

 utes after the operation. The abdomens were clipped from 

 several individuals; slight twitchings of the tarsi were the only 

 movements produced by the amputation. Seven letisimulating 

 individuals were decapitated with sharp scissors. Immediately 

 the legs relaxed and righting movements were made. These 

 investigators remind us that letisimulation occurs in almost all 

 orders of insects; that Holmes observed it in an amphipod 

 crustacean, and Andrews in the crayfish. It occurs rarely 

 among fishes and to some extent in the amphibia. It occurs 

 in several reptiles and birds and in a few mammals. Gee and 

 Lathrop agree with Holmes and with the Severins that this 

 form of behavior has developed out of thigmotactic propensities. 



DISEASE SPREADING INSTINCTS 



W. E. Britton (5, 6), C. T. Brues (10) and J. H. Paine (70), 

 have published helpful popular articles on the relation of in- 

 sects to diseases. 



Jennings (45) has discussed the method of controlling the 

 mosquitoes of the tropics, and W. E. Britton (6) the methods 

 of combating those of our Connecticut coast. The methods 

 advocated are well known to entomologists. 



C. T. Brues (n) gives a tabulated list of the diseases spiead 

 by insects and of the insects that spread them. He gives the 

 following reasons for believing that infantile paralysis is caused 

 by some insect: (1) the sporadic occurrence of the cases is 

 not easily explained on the basis of ordinary contact infection ; 

 (2) the seasonal distribution of the disease, showing the largest 

 number of cases during the warmer months; (3) its failure to 

 spread rapidly where many children are in close contact; and 

 (4) the characteristic rural nature of the disease. He gives 

 reasons why it is improbable that this disease is spread by 

 either the mosquito, the stable fly, the horn-fly, or fleas. He 

 suggests that it is spread by the tick; but he could find no 

 conclusive proof of this. 



C. H. T. Townsend (96) thinks that verruga fever is spread by 

 ticks in the same manner as the Rocky Mountain spotted fever. 



