The claims of cats as one of the rat remedies we shall have to dismiss in very short order, as the exceptional cases in which they do good work are altogether too few and far between. The only domestic animal which really possesses value in _hunting_ rats is the ferret, as, by reason of its india-rubber joints, it can pursue its prey home. Any terrier--no matter what variety--having a fair amount of intelligence can be broken in with ferrets, so that your ferret can do the hunting out and the dog--at the proper moment--can do the killing. The fox-terrier is by far the best ratting-terrier. He is quick, understands and remembers what is taught him, is full of ambition, and readily learns to regard the ferrets as his partners in the rat-hunt. IV.--HUMAN RAT-CATCHERS. The directions given with each of the remedies advocated by me are so plain that anyone can successfully put them into use. Where the rats have got altogether too thick, or where they hold possession of a place in such a way that there appears no clue to dislodging them, it is quite advisable to call in an expert. To this effect I have perfected a regular system of rat-exterminating in which the remedies I mention in this book are systematically applied--under my own superintendence--by a corps of experts. Through this improved system I am enabled to take contracts to exterminate rats (and also other vermin) from any kind of building in any city or town in the United States, providing the job is large enough. Correspondence on the subject given prompt attention. THE ORIGIN OF THE FERRET. WITH HINTS TO DARWIN. We have stated, in the first chapter of this book, that the verb "ferret" is derived from the animal of the same name, but many _savants_, and even "plain people," as Lincoln said, have cudgeled their brains trying to trace from whence the _animal_ has derived its name. After long and tedious delving into histories and musty tomes having even the slightest bearing on the subject, we are able herewith to enlighten these gentlemen. For this illumination they have long been waiting, we have no doubt, with the utmost anxiety and impatience. This requires us to go at length into the matter, and entails upon us the writing of the ferret's development from prehistoric times until merged into the animal of to-day, with its present shape, instincts, and habits. In the course of the essay we also prove conclusively that the animal originally comes from America. Many scientists will no doubt deem it peculiar to find us using many modern and untechnical terms in the following history, but let them rest assured that if we were to make use of our extensive scientific knowledge of the subject it would compel them to hunt up all the lexicons that had ever been compiled!