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diverticula which arise from the median sac. Ascer¬ 
tain that the posterior and some of the lateral diver¬ 
ticula are of extreme length, and pass round to the 
ventral surface, reaching to the neighbourhood of the 
anus, vulva, and even the rostrum (Fig. ioi). 
Some of the lining cells of the diverticula are 
especially large, and project freely into the lumen. 
These and other smaller cells become, during digestion, 
loaded with jet black granules. 
Or-nlfko d-oros 
Fig. ioi. Alimentary canal and appendages of Ornithodoros 
and Eurhipicephalus ( semi-diagrammatic ) 
C.G = coxal gland ; Ce.G = cephalic gland ; D = ventriculum ; 
A.D = anterior diverticulum; L.D = lateral diverticulum; 
P.D = posterior diverticulum; M.P.D. = median posterior 
diverticulum; E.P.D. — external posterior diverticulum; 
P = proventricuius ; R = rectum ; S — salivary gland; 
M.T. = malpighian tubule 
Some time after feeding, in the still partially fluid 
blood, a number of reddish granules are seen with the 
naked eye : they are really cells, wandering digestive 
