106 ENTOZOA. 



state, tliey do not appear to be very prevalent in the quadrumanous 

 tribes. The Gysticercus tenuicollis is tolerably constant in the 

 higher monkeys, and four distinct tapeworms have been found 

 in the Barbary ape {Inuus). The lemurs also harbour various Cys- 

 ticerci, and I have discovered a singular form of Goenwrus in the 

 limgs and liver of the common Madagascar species. Only a few 

 species of tapeworm have been noticed in Cheiroptera, and in the 

 Insectivora they are scarcely more abundant. In the true Carnivora 

 they are plentiful, and more particularly so in our domesticated 

 dogs. In the vegetable-feeding rodents the cestodes are by no 

 means uncommon, whilst those animals which partake of a mixed 

 diet, such as rats and mice, are still more liable to invasion. 

 Hitherto, no tapeworm appears to have been detected amongst the 

 edentulous mammals. The larger pachyderms and sohdungulates 

 harbour a few adult forms, but only the larvae appear to be 

 known in swine ; a true Taenia, however, has been described as 

 occurring in the aberrant genus Hyrax. The typical ruminants 

 are almost constantly infested both by mature and immature forms, 

 but in the camels larvae only have been detected. One or two 

 species are known to infest seals, and the same may be said of 

 Cetacea; the common porpoise harbouring an unusually large 

 form {Diphyllobothrium stemmacephalum) . In the marsupial 

 mammals the cestode parasites are comparatively rare. 



Birds. — Contrary to general expectation, the cestode entozoa 

 appear to be quite as abundant in the granivorous birds as they 

 are in the carnivorous hawks, owls, and buzzards. As yet, indeed, 

 we have no certain knowledge of their occurrence in the family 

 of vultures ; a circumstance arising probably from the few oppor- 

 tunities we have had for examining these birds in their wild state. 

 Cestodes abound in the woodpeckers, pigeons, partridges, phea- 

 sants, barn-fowls, and their allies, and they are scarcely less com- 

 mon in the bustards, emews, and ostriches. In the herons, plovers, 

 ducks, divers, gulls, and water-birds generally, the adult tape- 

 worms are extremely abundant, whilst their larvae are to be sought 



