L. E. Robinson and J. Davidson 
ferment-granules as seen in the alveoli of the first type, arc never visible 
in the “ Pyrainidenzellen.” 
Regarding the functions of the two types of alveoli which constitute 
the salivary gland of A. persicus, we, never having experimented with 
the salivary secretion, are unable to make any definite statement. The 
reader must be referred to the special work on this subject embodied in 
papers by Sabbatani', von Kiiussbergk and Nuttall and Strickland®. 
Nordenskibld discusses the probable functions of the secretions of the 
“ Funduszellen ” and the “ IVliindungszellen ” respectively^ but as his 
remarks are based on comparisons of the structure of these elements 
with similar structures in other animals, the function of which is 
definitely known, they are merely conjectural. There is, however, no 
doubt that one of the products of secretion of the salivary glands is an 
anticoagulin. Whether a digestive ferment is also secreted, remains 
unproven, and the existence of a venomous principle in the saliva, the 
presence of which has been surmised by many writers on the subject of 
tick biology, is still a matter of doubt. 
The Pharynx. 
Part I, Text-fig. 2; Plate V, figs. 16-20; Plate VI, fig. 21; 
Part II, Plates XV and XVI, fig. 1 ; Text-figs. 2 and 3. 
The pharynx is that portion of the alimentary canal which connects 
the buccal cavity with the oesophagus, and, in common with the majority 
of the Arachnida, it constitutes a powerful pumping organ which sucks 
in the fluid nutriment—blood in the case of ticks—and foxxes it into 
the stomach. 
The greater part of the organ is contained within the basis capituli 
but its posterior end protrudes for a short distance thi'ough the capitular 
foramen into the body cavity. Its anterior end is continuous with the 
buccal cavity, in the floor of which, as has been already seen, the 
pharyngeal orifice opens. The pharynx of Argas persicus differs from 
that of the Ixodid ticks in that the diameter of its middle portion 
greatly exceeds that at the extremities, thus giving it a shoi’t “torpedo” 
form. From the middle of its length the organ tapers in a curving 
manner towards either extremity, becoming much constricted at the 
1 Sabbatani, L. (1898). - Kiinssberg, K. von (1911). 
Nuttall, G. H. F., and Strickland, C. (1908). 
Nordenskibld, E. (1908), p. 653. 
