GOODE, J.

(after stating the facts). — We find no inconsistency between the first and second instructions. The first one submitted the case to the jury on the theory that a verdict for plaintiff was permissible if he was exercising care for his own safety at the time of the accident, and the motorman, after he saw, or in prudence ought to have seen the wagon on the track, could, by ordinary pare, have stopped the car in time to prevent the collision. This is, of course, the law. The second instruction submitted the case on the theory that if plaintiff Avas not exercising care for his own safety in respect of watching for cars, nevertheless if the motorman could have avoided injuring him by exercising ordinary care, the defendant was liable. ■ That is to say, the second instruction submitted the case on the theory *603that it is the duty of a person who observes another in a position where he is subject to injury by what the first person is doing, to take precautions to avert the injury. [Klockenbrink v. Railroad, 172 Mo. 678, 72 S. W. 900.] Both the instructions in their main scope and view of the law were sound. As to the criticism of the first instruction for imposing on the motorman the duty of stopping the Car after he saw the wagon on the track, instead of after he realized the danger of a collision, we may concede defendant’s proposition that the duty of a motorman to begin to get his car under control arises when he ought to realize there is danger of a collision. In other Avords, the mere presence of a vehicle on a track no- matter how far ahead of a car, does not call for instant action by the motorman to check the car’s speed. [Bell v. Railroad, 72 Mo. 50; Reno v. Railroad, 180 Mo. 469, 79 S. W. 464; Evans v. Railroad, 178 Mo. 508, 77 S. W. 515.] Nevertheless, the instruction as given is accurate. It told the jury that if the motorman, after he discovered the Avagon on the track, or by keeping the proper lookout would have discovered it, could have prevented the collision by using the appliances at hand to stop the car, the defendant aatis liable, provided the plaintiff did not contribute to the accident. It may not have been the motorman’s duty to begin to stop the car as soon as he saw, or ought to have seen the wagon; that would depend on circumstances. But it certainly was his duty to do so in time to prevent a collision if possible; and this is all the instruction told the jury.

The petition alleged permanent injuries and was sufficient in that regard, to let in proof. [Gerdes v. Iron Co., 124 Mo. 347, 25 S. W. 557.] The only injury to plaintiff AA-hich it is contended may be permanent, AAras the fracture of his right knee cap; but the physician AATho attended him testified this injury would not be permanent, and defendant’s counsel insist this state*604ment of the physician is conclusive, or rather, that there is no evidence tending to prove a permanent injury. It was shown all the injuries other than to the knee, Avere minor and healed quickly; that the tissues around the kneecap which were lacerated, would be reunited perfectly. At the time of the trial the kneecap Avas not as moAreable as formerly by reason of the callous 'substance aaLích was throAvn out by the bones or tissues in nature’s effort to heal. The physician further said he AArould not notice the motion of plaintiff’s knee was impaired from seeing plaintiff walk; that in ordinary locomotion no difference would be observed in the movement of the tAAro knees, but if plaintiff was running a difference would be noticed; that the condition of the knee would in no way interfere Avith plaintiff’s usual occupation. Plaintiff himself testified he walked fairly well, but if he wanted to climb' into his Avagon he had to creep up step by step, and that he could not jump as he could before he was hurt; that he could not work in the slaughter house as he did before; could not stoop' down as well, and in going upstairs had to take a step' Avith his sound leg and then bring his lame one up, instead of alternating Avith his feet from step to step. This testimony related to the condition of the limb at the time of the trial; which was in March, 1907.

The instruction on the measure of damages allOAved the jury to award damages for pain and mental suffering which plaintiff had endured and would endure; also damages for any permanent injury caused directly by the accident, if the jury believed to a reasonable certainty his injury would be permanent in nature and effect. ' Defendant’s counsel insist there was no evidence, to justify the court in instructing the jury they might assess damages for a permanent injury — no evidence from AAdiich such an injury could be inferred. The only witness who testified on the subject was the physician Avho attended plaintiff and was put on the stand by *605him. He swore unequivocally there would be no permanent injury. It is argued that the jury could judge of the permanency of the injury from the description of plaintiff’s hurts at the time of the accident and the condition he was in at the trial. But it strikes us that to do so would be going beyond the limit of legitimate inference. Though the injuries were originally severe they had practically healed and plaintiff’s inconvenience from them was not great. Under the circumstances of the case the doctor’s opinion was of much weight, but we do not hold it was conclusive. We do hold, however, that no evidence was adduced, either direct or circumstantial, positive or expert, to justify a jury in finding plaintiff was permanently injured. For this reason we hold that element of damages Was improperly included in the instructions.

The judgment is reversed and the cause remanded.

All concur.