LITERATURE FOR 1910 ON THE BEHAVIOR OF SPIDERS 

 AND INSECTS OTHER THAN ANTS 



C. H. TURNER 



Sumner High School, St. Louis, Mo. 

 TROPISMS 



Mitzmain '" concludes that the rodent flea is positively photo- 

 tactic in the early larval stages and negatively phototactic in 

 the late larval and adult stages. This induction was the result 

 of observing the reactions of the fleas upon the rodents, and 

 in the following experiment. A large number of fleas were 

 placed in a test-tube, the mouth closed with the thumb and 

 the tube held horizontally with the mouth away from the 

 window. All of the fleas jumped away from the window. When 

 the tube was reversed so as to have the mouth facing the window 

 the thumb could be removed without the fleas' escaping from 

 the tube. All would bound away from the light. When a flea 

 was placed within half an inch of the opening of the tube 

 and headed in that direction it did not escape, but turned about 

 and jumped away from the light. Even when the mouth of 

 the tube was tilted downwards the flea did not escape. This 

 experiment seems to indicate a real tropism, but one cannot 

 help regretting that it was not performed in a wide rectangular 

 rather than a narrow cylindrical enclosure; for in a narrow 

 cylindrical cage even those fleas that jumped obliquely side- 

 wise would be forced to land as though they had jumped di- 

 rectly away from the light. The movements of a flea are so 

 rapid that one is practically forced to judge the direction of 

 the movement by connecting the point of ending with the 

 place of beginning. 



Loeb claimed that, in water, blow-fly larvae are positively 

 geotropic, but not so under any other conditions. Recently 

 Mast " has conducted a series of well planned experiments, 

 in both air and water, which militate against this induction. 

 In the air experiments, the larvae were placed in glass jars. 

 The small larvae moved about in every possible direction; 

 the larger larvae crawled upwards, but frequently turned and 



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