CHAPTER IV.

PORCUPINES--CHINCHILLAS--AGOUTIS--CAVIES--HARES AND RABBITS--PIKAS.

HYSTRICIDÆ, THE PORCUPINES--Conversion of Hairs into Spines--Skull--Dentition--Tail--Sub-families--The True Porcupines--The Tree Porcupines--THE COMMON PORCUPINE--Distribution--Description--The Crest of Bristles--Nature of the Spines--Habits--Young--Flesh--On the Defensive--Other Species--Species of Tree Porcupines--THE COUENDOU--THE COUIY--Description--Habits--THE URSON, OR CANADA PORCUPINE--Description--Habits--Food--CHINCHILLIDÆ, THE CHINCHILLAS--Characteristics--THE VISCACHA--Description--Life on the Pampas--Their Burrows--Habits--The Chinchillas of the Andes--THE CHINCHILLA--THE SHORT-TAILED CHINCHILLA--CUVIER’S CHINCHILLA--THE PALE-FOOTED CHINCHILLA--DASYPROCTIDÆ, THE AGOUTIS--Characters--THE AGOUTI--Distribution--Appearance--Habits--AZARA’S AGOUTI--THE ACOUCHY--THE PACA--Appearance--Distribution--Habits--DINOMYIDÆ--Founded for a Single Species--Description--Rarity--CAVIIDÆ, THE CAVIES--Characteristics--THE RESTLESS CAVY--Appearance--Habits--The Guinea-Pig Controversy--THE BOLIVIAN CAVY--THE ROCK CAVY--THE SOUTHERN CAVY--THE PATAGONIAN CAVY, OR MARA--Peculiar Features--Its Burrows--Mode of Running--THE CAPYBARA--Its Teeth--Where Found--Habits--THE DOUBLE-TOOTHED RODENTS--Characteristics--LEPORIDÆ, THE HARES AND RABBITS--Structural Peculiarities--Distribution--Disposition--THE COMMON HARE--Hind Legs--Speed--Its “Doubles”--Other Artifices--Its “Form”--Habits--Food--Pet Hares--THE RABBIT--Distribution--Habits--Domesticated--THE MOUNTAIN HARE--LAGOMYIDÆ, THE PIKAS--Characteristics--Distribution--THE ALPINE PIKA--THE ROCKY MOUNTAIN PIKA 133