316 PROF. ROLLESTON ON THE PLACENTAL STRUCTURES OF THE TENREC. 
borders of the decidua serotina, along which the uterine mucous parapet was 
continuous with it, and passing underneath its two prolongations, ps", is seen 
the decidua reflexa, which is rudimentary in the Leporidz. 
Fig. 8. Vertical section of uterus of Rat (Mus decumanus) through utero-placental area, 
after parturition. ‘The letters u p show the line where the non-placental 
uterine mucous membrane became continuous with the decidua serotina 
which was discharged with the after-birth. The persistent non-deciduous 
serotina, which is inseparable from the circular muscular coat, forms a hernia- 
like protrusion out of, and not corresponding with, the curve of the uterine 
walls. A funnel-shaped depression leads down to it, and a lateral diverti- 
culum is thus appended to the uterine tube. The persistent serotina (Ps) and 
the circular muscular coat (c M) with which it is mixed up, filling up its inter- 
stices, is separated by an interval (sv), a little widened artificially, from the 
longitudinal muscular coat (Lm). The non-placental mucous membrane is 
much corrugated, owing to the contraction of the previously distended uterus. 
Fig. 9. Part of placenta, deciduz, and uterine walls of Pig-tailed Monkey (Macacus 
nemestrinus). The placenta (pL) has been artificially separated from the utero- 
placental area, and is kept in connexion with the uterus by a pointed process 
abutting upon its uterine aspect, and consisting of decidua vera, persistent, 
and deciduous serotine. A thin lamina of membrane (ps) is seen in the 
intervals between the placenta and the utero-placental area, being one part of 
the decidua serotina, tougher, more coherent, and more separable in this 
Simious than in the Human placenta. The persistent serotina (Ps) is loosely 
reticular, but limited towards the placenta by a smooth horizontally lying 
membrane, which would probably have been deciduous. The decidua reflexa 
(p R) is represented by a layer on the chorion (cu): it is separated by a wide 
interval from the non-placental uterine mucous membrane (u Mm), which might 
perhaps not have been deciduous (see Virchow, Gesamm. Abhandl. p.782). The 
‘‘ Decidua-Fortsitze” are well seen in the section of the placenta, as in the 
Human placenta at six months. (Cf. Schroder van der Kolk, cit. Priestley, 
l.c. p. 57, fig. 16, or Kdlliker, 1. c. pp. 148, 177, 183, and Ecker’s ‘ Icones 
Physiologicze,’ tab. 28. fig. 1, df.) 
