that a carrier is a passenger's servant in all cases. The rule has been overthrown in England, and is not in force in the United States courts, nor in most of the states.

§ 434. Children-Imputed negligence.-The question is only concerning children too young to be capable of exercising any care whatever; for if they have any capacity at all they will be negligent for failing to exercise it, and at the same time will be responsible only for their own negligence. Whether the negligence of parents or custodians shall be imputed to children who are themselves incapable of exercising care and hence incapable of negligence, is a question upon which the authorities are divided. The better reason is against imputing negligence in such case.

§ 435. Presumptions as to negligence.-As a rule negligence is not presumed, but must be proven. The mere fact that some one has been injured does not usually make it probable that any particular person has been negligent. But the circumstances under which an injury occurred may be such as to create a presumption of negligence, and throw the burden upon a certain person to prove himself without fault. If, judged by common human experience, a fact could not exist except by some negligence, the court will, in the absence of other evidence, declare that there was negligence. For instance, if a passenger is thrown down by the jerk of a street car, the presumption is that the jerk was by neg ligence of the street car company; if a boiler on a vessel explodes, it is presumed to have exploded by negligence of those in control. The presumption can

always be overcome by the defendant showing that in fact he exercised ordinary care under the circumstances.

Whether the presumption shall be made depends somewhat upon the nature of the duty owing and the degree of care required in its discharge. Where there is an obligation for especial care, the presumption of negligence will be made, when it would not under ordinary circumstances. For example, if a railroad train runs off the track and injures a passenger and a bystander, as to the passenger the presumption of negligence in the railroad company would arise, but not as to the bystander.

CHAPTER XXXII.

ANIMALS.

§ 436. Injuries by animals.-The subject of injury by animals is in some respects peculiar, partaking as it does of the nature both of nuisance and negligence. In this place, injuries caused by the voluntary act or purpose of the owner of the animals, will not be considered, for such injuries would usually be deemed an assault and battery by the owner himself.

In considering the law, a distinction must be kept in mind from the outset, between acts that are a trespass on land and acts that are not.

§ 437. Trespass upon land by animals.-Every unwarrantable entry by one's animals upon the land of another is a trespass, whether the land be enclosed or not. If any part of the animal cross the line the trespass is complete.

§ 438. Duty of owner at common law.-At common law every owner of animals was bound at his peril to keep his animals from straying upon another's land. The duty was absolute, and was not discharged by the exercise of the highest degree of care. Hence, no question of negligence was involved. The absolute obligation attached, however, only as to such animals as, from their nature, were capable of damaging land or crops. And an excep

tion was made in favor of the owners driving cattle along a highway, and in such cases the liability was not absolute, but the owner was relieved if he exercised ordinary care to prevent the trespass.

§ 439. The law in the United States.-The common law rule of absolute liability for injuries done by trespassing animals is generally in force in the United States. In some the wrong is not treated as negligence; in others it is called negligence, but the negligence is conclusively presumed from the fact of trespass. Statutes in the various states have modified the English rule to some extent by requiring land-owners to maintain sufficient fences.

§ 440. Remedies.-In addition to the usual remedy by an action for damages, the land-owner was entitled to take possession of the trespassing animal and keep it until the damage was paid. . Or he could drive the animal from his premises to the highway, using no more force than needful. For any excess he would in turn become liable himself.

§ 441. Animals not trespassing.-It was formerly held at common law that the owner of a wild beast, or a domestic animal known to be dangerous, was bound at his peril to keep it confined, and that it would be no defense that the owner exercised care to prevent injury. The dangerous animal was deemed a nuisance and the keeping it was an unlawful act.

The present rule is that for injuries done by an animal, other than by trespass, the owner is not absolutely liable, but liable only for a failure to use ordinary care. Whether the animal be dangerous. or tame, the owner is liable only for negligence. The care required must, of course, be proportioned

to the danger to be apprehended. In order to charge an owner or keeper for injuries by animals, it is nec essary to show that he had knowledge of the dangerous propensity and failed to take proper precautions.

§ 442. Owner's knowledge of danger.-Distinction is made, so far as the evidence of negligence in the owner is concerned, between (1) animals naturally vicious and (2) tame animals that have become vicious.

As to naturally wild and vicious animals, the presumption is conclusive that the owner knew them to be dangerous.

As to animals that have broken through the tameness of their nature and become vicious, there is no presumption that the owner knew of the dangerous propensity, but proof of a single breach brought home to the owner's notice is sufficient. Thenceforward they are to be treated the same as naturally wild animals.

As to tame domestic animals, the owner is bound only for a negligent failure to keep them confined, and then only for such injuries as from their nature they are likely to commit.