86. When case may be withdrawn from jury.

Unless there is some evidence of negligence the judge must not leave the issue of negligence to the jury, if there is one, and his failure to withdraw the case is a decision on which an appeal may lie1. If, at the close of the claimant's case, counsel for the defendant submits that he has no case to answer the judge may put him to his election whether he relies on his submission of no case, or whether he will call evidence himself