110 ON THE PLACENTAL STRUCTURES OF THE TENREC 



Matthews Duncan, ' Edinburgh Monthly Medical Journal.' September, 1853. 



Matthews Duncan, ' Medico-chirurgical Review.' October, 1853. 



Chisholm, 'Edinburgh Monthly Journal.' September, 1854. 



Bergmann andLeuckart, 'Vergleichende Anatomie und Physiologie.' 1855. 



Cazeau, ' Traite* des Accouchements.' 1856. 



Colin, ' Traite* de Physiologie Compare'e.' 1856. 



Chisholm, ' Edinburgh Monthly Journal.' January, 1857. 



Owen, 'Linnean Society's Proceedings.' February and April, 1857. 



Owen, 'Philosophical Transactions.' April 14, 1857. 



Matthews Duncan, ' Edinburgh Medical Journal.' December 1857, February 



1858, April 1859. 

 Kolliker, ' Entwickelungsgeschichte des Menschen und der hoheren Thiere.' 



Leipzig, 1 86 1. 

 Robin, ' De la muqueuse UteVine.' ' Mem. Acad. Imp. Medecine, Paris,' torn. xxv. 



1861. 

 Priestley, 'Lectures on the Gravid Uterus.' 1862. 

 Matthews Duncan, *On the Condition of the Uterus after Parturition.' 'Obstetrical 



Society's Transactions,' vol. iv. 1862. 

 Meigs, 'On the Reproductive Organs and Foetus of Delphinus Nesarnak.' 'Journal 



Acad. Nat. Sci. Phil.' vol. i. 267. 

 Birnbaum, ' Untersuchungen tiber den Bau der Eihaute.' Berlin, 1863. 

 Huxley, 'Lectures on the Elements of Comparative Anatomy.' London, 1864. 



Professor Huxley's views on the placental method of classification were made public 

 in his lectures at the College of Surgeons in the spring of 1853, and these lectures 

 were published about the same time in the ' Medical Times and Gazette.' This I 

 mention in order that the date appended to the last work on my list may not be 

 taken to imply a repudiation of the great obligations I owe to the teaching that book 

 contains. 



EXPLANATION OF PLATE 2. 



Fig. 1. Placenta of Tenrec (Centetes ecaudatus) detached from the deciduous serotina 

 and from the utero-placental area covered with persistent or non-deciduous serotina. 

 Part of the amnios, A, and of the umbilical cord, U C, are left in connexion with 

 the placenta, P L. The umbilical vessels are prolonged up into an upstanding 

 rim of membrane C H' which is itself an upward prolongation of the chorion, 

 and was continuous with the uterine tissues along a parapet of membrane U P 

 in fig. 2. 



Fig. 2. Utero-placental area of Tenrec. U P the parapet of uterine mucous membrane. 

 Within this is a quoit-shaped area of mucous membrane concentrically corrugated : 

 and within it is a space much perforated by orifices of blood-vessels and covered 

 with the non-deciduous or persistent serotina, P S. The presence of the ring of 

 corrugated mucous membrane bounding the non-deciduous serotina and bounded 

 itself by the circular parapet, U P, of mucous membrane, and the presence of an 

 upgrowth of the chorion, C H', continuous with this parapet, are phenomena, so far 

 as is known to me, unique in the Mammalia. 



Fig. 3. Section of uterine cornu and deciduous serotina of Guinea J*\g(Cavia aperca). 

 The deciduous serotina has been artificially displaced from its natural condition 

 of apposition with the non-deciduous serotina of the uterine wall. It is still 



