126 SPECIAL EXPRESSIONS: CHAP. V. The tail is extended, being curled or lashed from side to side. The hair is not erected—at least it was not so in the few cases observed by me. The ears are drawn closely backwards and the teeth are shown. Low savage growls are uttered. We can understand why the attitude as- sumed by a cat when preparing to fight with another cat, or in any way greatly irritated, is so widely different from that of a dog approaching another clog with hostile intentions; for the cat uses her fore-feet for striking, and tin's renders a crouching position convenient or necessary. She is also much more accustomed than a dog to lie concealed and suddenly spring on her prey. No cause can be assigned with certainty for the tail being lashed or curled from side to side. This habit is common to many other animals—for instance, to the puma, when prepared to spring;" but it is not common to dogs, or to foxes, as I infer from-Mr. St. John's ac- count of a fox lying in wait and seizing a hare. Wo have already seen that some kinds of lizards and various snakes, when excited, rapidly vibrate the tips of their tails. It would appear as if, under strong excitement, there existed an uncontrollable desire for movement of some kind, owing to nerve-force being freely liberated from the excited scnsorium; and that as the tail is left free, and as its movement does not disturb the general position of the body, it is curled or lashed about. All. the movements of a cat, when feeling affection- ate, are in complete antithesis to those just described. She now stands upright, with slightly arched back, tail perpendicularly raised, and ears erected; and. she rubs her cheeks and flanks against her master or mistress. The desire to rub something is so strong in cats under this state of mind, that they may often be seen rubbing 0 Azara, ' Quadrupedes du Paraguay,' 1801, torn. i. p. 136.