Structure and Nutrition of the Cornea, Cartilage and Wharton's Jelly

Abstract

WE have read with great interest the letter by-Barcroft et al.¹. Barcroft and his co-workers observed the passage of large molecules in Wharton's jelly of the umbilical cord of fœtal sheep, and they believe that there exists a non-vascular pathway through which nourishment travels along from the placenta towards the fœtus. While there seems to be every justification for this interpretation of the findings, we are of the opinion that this easy and relatively fast passage of large molecules may contribute to the nutrition of Wharton's jelly itself. With a few exceptions² (apart from the large umbilical vessels, which are not supposed to give off nourishment for the surrounding tissues) the substance of the umbilical cord is completely avascular. In this respect Wharton's jelly is closely similar to cartilage and the cornea. It is generally accepted that both cartilage and the cornea are nourished by diffusion from the surrounding tissues, and it seems to us that to assume a similar method of nourishment for Wharton's jelly is entirely justifiable. Both Wharton's jelly and cartilage are rich in two closely related substances, mucoitin sulphuric acid and chondroitin sulphuric acid respectively.