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to hold together the particles of soil. "Where the cocoons were 

 made on the sides of the vials I was ahle to see through the 

 thin web and note the transformations inside. The following 

 gives a brief summary of the various stages: 



This makes a total of 22 days from egg to adult; other 

 records gave from 21 to 20 days, hence the life cycle is about 

 3 or 4 weeks. 



ACTIVITY OF ADULTS. 



Fleas that emerged April 15th were put into a large glass 

 jar with a young rooster. A careful chart was made of the 

 top of the head, showing the distribution and sex of each of 

 the fleas. It was found that the males move about during the 

 night, being attached in different positions each morning — 

 usually near females. They began dying after 2 days and 

 at the end of 6 days all were dead — many of them in situ, 

 with their beaks attached to the skin. The females, unless 

 disturbed, remained attached in their original positions. After 

 18 days the first one died a natural death. The others died 

 from three to four weeks after emergence, and a single female 

 lived 40 days, producing eggs up to the time of her death, 

 and, upon dissection, the ovaries were found to contain numer- 

 ous developing ovules. 



EGG LAYING. 



Gelatin capsules were attached over several of the females 

 to determine their egg-records. It was found that most of 

 the eggs were laid at night, — under favorable conditions as 

 many as 40 being deposited, while during the day only 2 or 

 3 were produced. Another interesting observation was that 

 the females with males located near them laid many more eggs, 

 and that their record dropped off decidedly, after 2 days, if 

 the males were removed. Experiments were tried of intro- 

 ducing new males with females that had ceased laving, and it 



