21st. It is also in cases where changes have been proved that we most often have abnormal shortness, knots and bands of the cord.
22d. The permanency of the presentation increases towards the end of pregnancy. (Law 3, of Schultze.) 23d. This applies to primiparEe as well as to multiparm 24th. It is especially the presentations that do not change towards the end of pregnancy.
25th. After the fortieth week mutation of the presentation in primiparie has never been encountered.
26th. But we can prove that there occur in them changes in position up to the thirty-ninth week. (The opposite of Schultze No. 6, Law.) 27th. Permanent fixity can only be seen in the last weeks of pregnancy.
28th. In multiparEe the presentation can change until the thirtieth week. In primiparEe, in spite of fifteen examinations, the presentation has remained fixed after the thirtieth or thirty-first week.
29th. The proportion of changes of presentation, as compared with changes of position, remains about equal during the ninth and tenth month in primiparEe (the opposite of Law No. 8, of Schultze). During
the seventh and eighth month presentation changes are commoner than those of position.
30th. The second position changes nearly as often into the first, as the first does into the second.
31st. Taken as a whole, the mutations result, in nearly half the cases, in the production of the first position of the vertex.
32d. If in 418 women, at the end of pregnancy, the relative frequency of the first position of the vertex is increased, it results less from a trans formation of the second position into the first, than from the transforma tion of other positions into it. Tarnier and Chantreuil claim that changes of position are commoner than changes of presentation; that the trans formation of vertex into breech is very rare, while other presentations often change into vertex, and especially into OLA. That is to say, the changes tend to bring the foetus into the most favorable position—the first of the vertex.