440 On the Anatomy of the Umbilical Cord. 



EXPLANATION OF THE PLATES. 



Plate 11. 



Fig. 1. Median section of cord, skowing the dermal ring to extend further on the 

 cord on the npper or venous side than on the lower (actual size). 



Fig. 2. Surface of cord and dermal ring, dissected off and laid flat, showing the capil- 

 laries of the former and the camb-like projection of the latter (actual size). 



Fig. 3. Surface of cord, silver-stained, and epithelium partly removed ( X 1000). 



Fig. 4. Transverse section of cord, showing one of its three columns injected ( X 120). 



Fig. 5. Canalicular tissue of cord, injected (x 250). 



Fig. 6. Ditto, with nuclei stained ( x 200). 



Fig. 7. Nuclei of canalicular tissue, highly magnified (x 1000). 



Fig. 8. Ditto, with canals uninjected ( X 250). 



Plate 12. 



Fig. 9. Round wandering cells in alveoli (x700). 



Fig. 10. Round cells, highly magnified ( X 1000). 



Fig. 11. Ditto in neighbourhood of capillary, and some invading the blood-clot 

 (X1000). 



Fig. 12. Two umbilical arteries, with central sinus of cord lying near them ( X 20). 



Fig. 13. Median section of cord and omphalic structures, with canalicular tissue (at 

 arrow) injected on the one side of the ring, and on the other the sub- 

 cutaneous tissue injected (actual size). 



Fig. 14. Terminal cone of canalicular tissue, injected (X 120). 



Plate 13. 



Fig. 15. Central sinus of cord, with its branches and canalicular tissue injected from 



them ( X 20). 

 Fig. 16. Capillary of cord, one inch from dermal ring, showing its relations to the 



lacunar spaces and resemblance to Haversian system ( X 200). 

 Fig. 17. Two layers of the external coat of an umbilical artery ( X 200). 

 Fig. 18. Diagram of the same. 

 Fig. 19. Drawing of roots of origin and course of central sinus of cord (by Mr. 



Priestley Smith, actual size). 

 Fig. 20. Transverse section of umbilical artery, showing rugae ( X 20). 

 Fig. 21. Capillaries running on to the cord from the dermal ring : a, showing method 



of origin ( X 3) ; b, actual size. 



Plate 14. 



Pig. 22. Arrangement of wandering cells on ruga? of contracted artery for closing it 



(X 1000). 

 Fig. 23. Retrograde change in muscular coats of arteries ( X 1000). 

 Fig. 24. Endothelium of vein, silver-stained (X 1000). 

 Fig. 25. Inner surface of contracted artery, silver-stained ( X 500). 

 Fig. 26. Inner surface of distended artery, silver-stained ( X J)00). 



