126 



LECTURE V. 



FIG. 40. 



eyes, I mean the umbilical cord. Its substance (the so- 

 called jelly (gelatina) of Wharton*) is also formed by 

 one of those tissues which certainly contain vessels, but 

 yet really possess none. The vessels which are trans- 

 mitted through the umbilical cord, do not immediately 

 contribute to its nourishment, at least not in the sense in 

 which we speak of nutrient vessels in other parts. For 

 when we speak of nutrient vessels, we always mean ves- 

 sels which have capillaries in the parts which are to be 

 nourished. The thoracic aorta is not the nutrient ves- 

 sel of the thorax, any more than the abdominal aorta, or 

 the vena cava, is that of the abdominal viscera. We 

 should expect, therefore, in the case of the umbilical 

 cord to find umbilical capillaries in addition to the two 

 umbilical arteries and the umbilical 

 vein. But these arteries and this 

 vein run their course to the placenta, 

 without giving off a single small 

 vessel, and it is only when they have 

 reached that body that they begin to 

 ramify. The only capillary vessels 

 which are found in the whole length 

 of the umbilical cord of a somewhat 

 developed foetus do not extend more 

 than about four or five lines (in rare 

 instances a little farther), beyond the 

 abdominal walls into that part of the 

 cord which remains after birth. The 



Fig. 40. The abdominal end of the umbilical cord of a nearly full-grown foetus, 

 injected. A. The abdominal wall. B. The permanent part of the cord with a 

 congeries of injected vessels along its border. 0. Its deciduous portion with the 

 convolutions of the umbilical vessels, v. The limits of the capillaries. 



* Lymphaeductus, vel gelatina, quce eorum vices gerit, alterum succum albumini 

 ovorum similorem abducit (a placenta) ad f^iniculum umbilicalem. (Thorn. Whart. 

 Adenographia, Amstelaedami, 1669, p. 233.) 



