PLACENTAL STRUCTURES OF THE TENREC. 289 
“* serofina,” or to the now exploded theory which the word was intended to bring 
before the mind) to call ‘‘ deciduous serotina’”’ ; the utero-placental mucous area (fig. 2) 
I would call ‘‘ non-deciduous serotina”’ ; and the spongy structure (fig. 1) made up of 
villi and umbilical vessels, and, in all placental mammals (except Cetacea, Artiodactyles, 
and Perissodactyles, and possibly Bruta), of more or less maternal structure inextricably 
intermixed as well, I would call ‘ placenta.” The word ‘‘after-birth’’ includes 
“placenta” and “deciduous serotina,” both usually, though not invariably, coming 
away together. 
Owing to errors of observation, the name “ decidua serotina”’ has been applied to 
the structure I would call ‘‘ non-deciduous serotina,” as well as to that to which Dr. 
Priestley’, like myself, would limit it. It is called ‘‘ parietal decidua” by Professor 
Goodsir?, and ‘‘ caduque intero-placentaire”’ by M. Robin*. And in an account of 
it given by Professor Kélliker, I find him speaking of it in the Human subject as 
‘‘eine zusammenhangende Haut wenn er gut erhalten ist’’*. It is sometimes called 
‘‘placenta materna’’; but this phrase is applied to the maternal element of the 
“* placenta” also, and the adoption of it would consequently cause confusion. That the 
utero-placental area is, after parturition, covered by a layer of mucous tissue, and that the 
muscular coat is not laid bare at that period, but protected by a more or less consistent 
and coherent coating, to which I would affix the name of ‘‘ non-deciduous serotina,”’ was 
clearly shown, in the year 1853, by Dr. Matthews Duncan’, and has been subsequently 
confirmed by Drs. Chisholm and Priestley® in Great Britain and by M. Robin in France. 
This is not the place for histological and pathological details, such as will be found 
in the literature to which I have just referred ; but, from a zoological point of view, it 
may be remarked that the fact of the non-regeneration of the uterine cotyledons of the 
Ruminant, after accidental separation of them from the uterine wall, lends the strongest 
confirmation to Dr. Matthews Duncan’s views. It has been most satisfactorily shown’ 
that, after such an occurrence, the place of the lost cotyledon is occupied not by fresh 
mucous membrane, but merely by a white cicatrix. 
I will now proceed to contrast and compare the foetal and maternal structures in 
connexion with the placenta of certain other mammals with their homologues already 
described in the Tenrec. 
* On the Development of the Gravid Uterus, pp. 22 & 48, 1860. 
* Anatomical and Pathological Observations, 1845, p. 60, pl. 3. fig. 6. 
* Mém. Acad. Imp. Méd. Paris, 1861, tom. xxvi. pp. 131 & 141, where there is a disquisition on its histology. 
See also Cazeau, ‘Traité des Accouchements,’ 1856, pp. 192 & 202. * lc. pp. 145 & 158. 
* Edinburgh Monthly Med. Journ. Sept. 1853. See also Medico-Chirurgical Review, Oct. 1853; Edinburgh 
Month. Med. Journ., Dec. 1857, Feb. 1858; Obstetrical Society’s Trans. vol. iv. April 1859, May 1862. 
° Edinburgh Monthly Med. Journal, Sept. 1854; id¢d. Jan. 1857. 
7 M. Goubaux, cit. Colin, ‘ Physiologie Comparée,’ vol. ii. p. 612. 
