IMPOUNDIl^G WATER TO CONTROL BREEDING OF MOSQUITOES. 



point of origin of the bayou to its junction with Roundaway, the dis- 

 tance in an air line is only 7^ miles. The bayou, however, travels a 

 distance of over 31 miles. The section of Bayou Walnut in its course 

 through Hecla plantation is shown in Figure 1. The average fall of 

 the bayou in this section is 0.6 foot to the mile. 



ae. 3C//?B9(/OF £A/rOAfOW3Y 



Fig. 1. — ^Map of section of Bayou Walnut near Mound, La., showing impounded area 



and surroundings. 



During 1914 it was observed that under natural conditions there 

 was practically no breeding of Anopheles in certain restricted sec- 

 tions of the bayou where open water occurred, where the bed was 

 free of vegetation, and where the margins were clean. On the other 



