Hygienic Laboratory, Bulletin -16. 
Plate XII. 
Z5/^. 
From a horizontal section of a mite 48 hours after feeding upon an infected rat. Figure repre- 
sents the anterior portion of the left lateral diverticulum of the ventriculus in section. Stained 
with iron hematoxylin, a. Epithelial and muscular layer of ventriculus; h, zygotes and 
ookinets of various forms. Drawn with camera lucida. 
