Fleas 



the writer's office in Washington, showed that the larva casts its 

 first skin in from three to seven days, and its second skin in from 

 three to four days. From seven to fourteen days after hatching, 

 they began to spin a delicate silken cocoon, which, when com- 

 pleted, was almost transparent, except where it was covered 

 with dust particles. In the cocoon the pupa, as shown in the 

 accompanying figure, was formed and the insect remained in 

 the pupal condition for four days. Thus an entire generation 

 may be developed in about a fortnight, and since the adult 

 female lays many eggs, it is not surprising that persons having 

 cats or dogs about the house will frequently (and especially 

 where the houses are closed during the summer, and the floors 

 left unswept) find their domiciles overrun with thousands of 

 these active, biting creatures. 



The remedies consist in a free use of fresh pyrethrum 

 powder, in spraying the floors and floor coverings with benzine 

 or in thoroughly washing the floors with hot water and soap. 

 On pet animals pyrethrum powder should be freely used. 



194 



