On the Female Organs and Flacentation of the Racoon. 297 



In conclusion, it may be as well to summarise the observations con- 

 tained in the foregoing pages. These show : — 



1. That Frocyon agrees with all the other Carnivora in which that 

 organ has been hitherto examined in the possession of a zonary or 

 annular placenta. 



2. That similarly Frocyon agrees with all in the mode of interlock- 

 ing of the foetal and maternal portions of the placenta, and in the 

 consequent deciduate character of that organ. 



3. That Frocyon agrees with the members of the plantigrade section, 

 at the same time that it differs from those composing both the digiti- 

 grade and pinniped sections of the Carnivora, inasmuch as at one spot 

 the placenta presents a gap or deficiency, at which spot the placental 

 structure is imperfect. 



4. That Frocyon agrees with Canis at the same time that it differs 

 from Felis, in the absence of a continuous layer of decidua serotina 

 from the uterine surface of the detached placenta. 



5. That Frocyon differs from every other Carnivore, the placenta of 

 which has been minutely examined, in the possession of placental 

 vessels possessed of a structure hitherto only met with in the placenta 

 of Cholcepus Foffrnanni among the Edentates. 



6. That Frocyon differs from every other Carnivore, the foetus of 

 which has been hitherto examined, in the non-possession of an umbilical 

 vesicle. 



7. That Frocyon differs from all Carnivora of which the young 

 have been hitherto examined, inasmuch as the foetus is provided with a 

 supernumerary cuticle or epitrichium, a structure which has only been 

 met with in the young of certain members of other mammalian groups. 



EXPLANATION" OF PLATES. 



I have to acknowledge, with thanks, the kindness of my friend, Mr. Alfred 

 Young, in drawing the accompanying excellent illustrations of the microscopic 

 anatomy of the placenta and uterine mucous membrane. 



Plate 3. 



Figure 1. Exterior of the female organs of Vrocyon lotor in the gravid state, two- 

 thirds natural size. B.C. Eight cornu uteri in which the foetus was 

 lodged. B.C. Left cornu uteri, o.o. Ovary encircled by the Fallopian tube. 

 l.d. l.d. Ligamentum diaphragmaticum uteri. L.T. l.t. Ligamentum teres 

 uteri. L.L. Ligamentum latum uteri. B. Bladder. 



Figure 2. The foetal membranes after removal from the uterus. As stated in the 

 text, the membranes were ruptured when the specimen came into my 

 hands. Their appearance, after I had divided the placental belt 

 and removed the foetus, is faithfully reproduced in this figure. 

 A. Amnion. c.C.C. Chorion, p.p. Placenta. The umbilical vessels are 

 seen ramifying on the foetal surface of the latter. 



x 2 



