LETTER OF TRANSMITTAL 



U. S. Department of Agriculture, 



Bureau of Entomology, 

 Washington, D. C, Septemher 1, 1911. 

 Sir: At frequent intervals and for many years the Bureau of 

 Entomology has been ap])ealed to by medical men and others to 

 determine insects said to have been passed by sick people. The 

 majority of these insects have been maggots (larvae of Diptera). 

 The characteristics distinguishing these larvae have not been well 

 understood, and the accompanying manuscript is the result of a 

 competent effort by Mr. Banks to assist workers in the study of 

 internal myiasis. I recommend that it be published as No. 22 of the 

 Technical Series of this bureau. 



Respectfully, L. O. Howard, 



Entomologist and Cliiej of Bureau. 

 Hon. James Wilson, 



Secretary oj Agriculture. 



