Defendants assign as error the refusal of the trial judge to grant defendants’ motion for judgment of involuntary nonsuit. Defendants contend that plaintiff’s evidence discloses that she was contributorily negligent as a matter of law. We do not agree.

Whether, under the circumstances as disclosed by the evidence, plaintiff, in the exercise of that degree of care which a reasonably prudent person would exercise for his own safety, could or should have seen the pipe was a question for jury determination under proper instructions from the Court. It was likewise for jury determination whether plaintiff exercised due care for her own safety in walking down the pedestrian ramp under the circumstances disclosed by the evidence. And further, it was a question for jury determination whether plaintiff acted as a reasonable and prudent person in momentarily turning her head when Mrs. Matthews called out to her to “watch out.” This assignment of error is overruled.

Defendants assign as errors (Assignments Nos. 1 and 2) that .the trial court admitted testimony concerning the absence of a red flag on the end of defendants’ load of pipe, and admitted testimony concerning the custom of parking trucks at the Garver Manufacturing Company plant. These assignments of error are overruled.

Defendants’ assignment of error No. 3 is not discussed in their brief and is therefore deemed abandoned. Rule 28, Rules of Practice in the Court of Appeals of North Carolina.

By assignment of error No. 7, defendants contend the Court erred in its charge to the jury. Since there must be a new trial we do not deem it necessary to discuss this assignment of error.

Defendants assign as error that the trial court allowed plaintiff to testify concerning treatment at Duke University Medical Center in January 1968 without showing connection between the 16 March 1966 accident and the necessity for the treatment received in 1968. This assignment of error has merit.

Plaintiff offered evidence, through her own testimony and that of the doctor, that she was treated immediately after the accident by Dr. Hooper Johnson; that he hospitalized her for a fracture of her nose and a fracture of the middle third of her face. This fracture was demonstrated by observing motion when pressure was applied to her upper teeth; it was treated by securing a wire from the back teeth onto the cheekbone on both the right and left side. The wires were removed on 22 April 1966; the doctor felt that he got good results; and he did not see plaintiff again until 20 January 1969.

*721 Plaintiff further offered evidence, through her own testimony .and that of the doctor, that she was examined by Dr. Robert A. Moore in November and December 1966. Dr. Moore detected some .swelling and tenderness over the right cheek and the upper jaw, the right maxilla.

Thereafter plaintiff was allowed, over objection, to testify that in December 1967 (approximately a year after her last visit to Dr. Moore) she saw a Dr. Dorman; where and for what is not dis■closed. Plaintiff offered no evidence from Dr. Dorman. Also, over •objection, plaintiff was allowed to testify that she was operated on .at Duke University Medical Center in January 1968 (approximately twenty-two months after the accident, and over a year after the •complaint was filed in this action). It is interesting to note that when plaintiff first mentioned Duke University Medical Center in Jher testimony, it was in reply to a question from her counsel as .follows:

“Q. Did you have some loss subsequent to that?

“A. Yes, when I went to Duke.

“OBJECTION.

“MR. GOLDBERG: I am not contending for it.”

The only reasonable interpretation of counsel’s reply to the objection is that plaintiff was not contending she was entitled to •damages by reason of whatever treatment she received at Duke. Nevertheless, plaintiff was allowed to continue with testimony of •expense and loss of time from work by reason of her treatment at Duke. Plaintiff was allowed to testify, over objection, that at Duke: “They cut the ends of my jawbone off to relieve some of the pressure.” ‘There is not a scintilla of medical evidence to relate the necessity for ■such an operation to the March 1966 accident. In order for plaintiff to be entitled to recover damages for the hospitalization at Duke University Medical Center, she must show that the damages claimed were the natural and probable result of the negligence complained of. 3 Strong, N.C. Index 2d, Damages, § 2, p. 165. There are no facts .in evidence from which a layman of average intelligence would know what caused the necessity for the operation in January 1968, and the jury could only indulge in speculation as to why it was neces•sary to cut off the ends of plaintiff’s jawbones. “Where ‘a layman •can have no well-founded knowledge and can do no more than indulge in mere speculation (as to the cause of a physical condition), there is no proper foundation for a finding by the trier without expert medical testimony.’ ” Gillikin v. Burbage, 263 N.C. 317, 139 S.E. 2d 753.

*722 The admission of this testimony without proper connection and foundation constituted prejudicial error which entitles defendants to a

New trial.