Screening and Destruction 205 



numerable avenues for the entry of mosqviitoes. 

 To enumerate a few of these: cracks and knot 

 holes in the floor; ill-fitting doors; spaces between 

 a corrugated iron roof and the plate left uncalked; 

 cracks in the siding of an unsealed frame building; 

 open spaces around plumbing, stove pipe, etc. 

 In the Canal Zone, with the extreme variation 

 in humidity between the dry and wet seasons, 

 defects develop constantly in the woodwork of the 

 light frame constructions employed. The screen- 

 ing is also exposed to rather severe strain. To 

 maintain efficiently the mosquito-proofing of 

 the dwellings, a weekly inspection was made of all 

 the screened houses, and the needed repairs noted, 

 and made at once. Since 1908 the repairing of 

 screening has been delegated to the Quarter- 

 master's Department for administrative reasons. 

 From the standpoint of sanitation, it is wiser to 

 maintain a screen-repairing force under the 

 immediate control of the sanitary authorities, to 

 instire this important work being done by a force 

 specially trained to detect defects in mosqmto- 

 proofing, and to render dwellings mosquito-proof 

 unhampered by the interference of other duties. 

 After experience with both systems, the writers 

 earnestly recommend that all questions of mos- 

 quito-proofing shotdd be entrusted to the sanitary 



