"It is altogether exceptional for the mother, healthy at the moment of conception, not to participate in the disease transmitted by the father to the child. If she escapes direct contagion—which is rare when the disease of the father is active—she undergoes a species of infection from contact with the contaminated foetus.

"Syphilis by conception, which is thus transmitted from the foetus to the mother, may present the usual characters and evolutions of the acquired disease; frequently, also, it is latent, and is betrayed only by the existence of immunity from further contagion on the part of the mother. It may finally manifest itself by tertiary symptoms or by systemic troubles without specific characters.51

51 "This form of syphilis shows itself in the mother in three ways:

"1st. By the usual signs of syphilis by contagion, with the exception of the primary sore, appearing about the sixty-fifth day after conception.

"2d. Appearing at a later date as secondary or even as tertiary symptoms, and preceded merely by a little disturbance of the general health, unhealthy appearance of skin, falling of hair, etc., but nothing truly specific.

"3d. Showing itself some years afterward in a tertiary form, having in the mean while given no indication of its existence save only in the protection it afforded against contagion from the child" (Nouveau Dict. de Méd. et Chir., vol. xxxiv. p. 696).

"The power of transmitting syphilis hereditarily decreases spontaneously as the disease of the parent becomes older. The influence of treatment is no less certain than that of time. When the two progenitors are at the moment of conception free from syphilis, the foetus may still be infected if the mother acquire the disease during her pregnancy."

Syphilis of the placenta is of especial interest in its relation to the abortions and stillbirths so frequent in syphilis. Until the elaborate paper of Fraenkel upon this subject (see foot-note, [p. 265]) almost nothing was known about it. He describes52 the macroscopic changes as consisting of increased size and weight of the placenta, closer and firmer texture of the placental tissue, the presence of old and recent extravasations of blood in all stages, opacity and thickening of the decidual covering and of the amnion and chorion, which are in places adherent to each other. Microscopically, it was found that the placental villi were filled with small nucleated cells, which were especially abundant in the centre of the villous spaces along the axis where the vessels usually take their course. The ends of the villi were enlarged with knob-like processes.

52 I condense here from the translation of Fraenkel's paper, which constitutes the bulk of chap. xxvii. of Bumstead and Taylor's excellent work.

Fraenkel's explanation of these changes is as follows: Under the influence of syphilis53 cell-proliferation begins in the villi, which are, normally, only sparingly supplied with cells. These new cells excite proliferation of the cells of the connective-tissue stroma and of the epithelium. This proceeds to such an extent that it leads to compression of the vessels,54 interfering with the circulation, and finally obliterates them. The vascular spaces into which the villi dip become filled up and narrowed, and often disappear. In this way, and also by reason of the thickening of the epithelium, the interchange between the maternal and foetal blood is interfered with, and at last is prevented.