250 
Ar<fas persicus 
The Excretory System. 
In addition to the previously described Malpighian tubules (p. 238) 
a pair of coxal glands is developed in Argas persicus, the function of 
which is probably concerned with the excretion of waste products. The 
subject is one which requires further investigation before any definite 
opinion can be expressed. 
The Coxal Glands. 
Plate XVII, fig. 9 ; Text-fig. 8. 
The coxal glands, which were first observed in Ornithodorus by 
Christophers, and subsequently described in 0. moubata by von Klinss- 
bergh appear in A. persicus as a pair of very small glandular masses 
which lie immediately above the second pair of coxae. They are to be 
Fig. 8. Argas jiersicus ? . Longitudinal section passing through coxae i and ii, showing 
the duct of the coxal gland and its external opening in the coxal interspace, x 100 diam. 
recognised with difficulty in dissections of the entire animal, but are 
readily seen in sections (see PI. XVI, fig. 2, o. ex. gl.). Each gland comsists 
of a small number of relatively large alveoli which are each separately 
connected with the main duct by a short efferent duct. In some respects 
the alveoli resemble thePyramidemellen of the salivary glands (see p.224). 
The nuclei are very large and kidney-shaped; they are rich in chromatin 
which is disposed in coarse flecks, and always contain one or more large 
1 Kilnssberg, K. von (1911). 
