Plate LXIII 

 the hog louse, haematopinus suis linne 



1, Transverse section through stomach nine hours after feeding, x 1925 (a. region of section enlarged 

 in 2); 2, region a of 1, x 600; 3, transverse section through intestine and reproductive organs of male, 

 X 290 (a, intestine; b, seminal vesicles containing spermatophore; c, muscular part of ejaculatorj' duct; 

 d, slender part of ejaculatory duct; e, vasa deferens; f, upper region of seminal vesicles which acts as 

 reservoir for spermatozoa; g, malpighian tubes; h, tra'chea) 



736 



