V. cord is composed of the arteries and the umbilical vein, surrounded by Wharton's jelly, a transparent, colorless, gelatinous substance (inter•annexial tissue of Dastre), in which Renaut distinguishes a mueoid tissue properly so-called, and a peri-vascular tissue. In rare cases there are two umbilical veins and a single artery. The arteries run side by side, and form a spiral chain around the vein. According to Hyrtl, each vessel possesses besides this a twist proper to itself, turning spirally upon its own proper axis. Hyrtl and Berger have proved, by means of inflated and dried cords, that the arteries and veins are provided with valves composed of the full thickness of the walls. The arteries possess but one internal coat, so that the blood only progresses under the influence of the festal heart beat. The valves may be semilunar or cir cular, and sometimes several of them unite to form a perfect diaphragm pierced by a hole in the centre. The number of valves in the vein is very variable. Veins that are not at all or but little tortuous, have no valves, or only traces of them. Very tortuous veins, on the contrary, very often have a large number of valves a few lines in height. Berger denies that these are valves, and calls them simply semilunar folds.
The cord has no lymphatic vessels. Schatt and Valentin have described nerve filaments, which Miller has been able to follow to 3 to 4 inches 'from the umbilicus. Virchow, on the other hand, denies their existence.
VI. Rings formed by the cord may encircle various parts of. the fcetus. They have been found as follows in order of their frequency: 1st. Around the one or two coils, though we have seen three and four. Chantreuil, Rouz6, Bailey, and Campbell have seen six coils, Baudelocque seven, and bilme. Waldwogel eight.
2d. Around the Trunk., when they may or may not include the mem bers.
3d. Around the a rule there are at the same time coils around the neck or trunk, or more or less complicated twists and knots. A most curious case of this kind has been described by Treat. (Fig. 152.) Rings of the cord are of common occurrence, being found at least once in every 5 or 6 deliveries. As a rule they encircle the neck; in 967 cases observed at the Clinic, 953 cases were of that variety, against 14 cases where trunk or members were involved. The causes are: Length of the cord, excess of liquor ammni, a small foetus, exaggerated movements of mother and child, and finally, certain individual predispositions.
The signs are either those of accidental or relative shortness of the cord, which we shall shortly consider, or other signs peculiar to these bands. Thus Cbarrier and Winckel have plainly felt, by abdominal pal pation, a loop of the cord running across the hack of the fcetus. In a cer
tain number of cases a bruit de souffle called the umbilical souffle may be detected; it is isochronous with the foetal pulse. These signs are neither constant nor certain.
But these usually harmless loops and bands of the cord may in some cases hinder labor, or even cause the death of the child. Mayer saw 49 out of 685 cases of this kind die, 18 fatal cases of which were due solely to the existence of the loops. Veit, in 442 cases, records 63 as appa rently stillborn, and seven as dead. The dangers depend upon the pres entation, the seat and number of the bands, and the degree of constriction. In breech presentations and when around the neck they are most danger ous. Elsewhere it is only the possible compression of the cord which may compromise the life of the fcetus. For not only may asphyxia result from the compression, but the obstruction to the return circulation may cause congestion of the brain; and the pressure may even result in the cutting through of soft and hard parts by the ligature. Cases of this latter kind have been reported by Bailey, Blume (Fig. 153), Siebold (Fig. 154), Bartscher, Heyfelder, Eichorn, Credl., Buchanan, Owen, Morgagni, Mont gomery, Adams (Fig. 155), Beaty, (Fig. 156), Hillairet, (Fig. 157), etc. See also Figs. 142 to 147.
During pregnancy there is no treatment for this accident. At labor the only thing to do is to disengage the entangled parts as rapidly as pos sible, and, if this cannot be done, to cut the cord and end the labor with all possible speed. If the child is endangered before the head is engaged, apply the forceps.
In twin-births entanglements with the cord are rarer. Chantreu i 1 states that Fricke found only 9 cases, 5 of bands, 2 of knots, and 1 of knots and bands. In these 9 cases there were 4 deliveries at term, 2 be tween 7 and 8 months, and 3 abortions at the third to the fourth month.
VII. Shortness of the cord may be absolute or natural, or relative, from twists and knots. The shortest recorded cords are those of Sclafer, which was hardly half an inch long ; Malgaigne, 2.7; Meissner, bale, 4.5 inches; and Depaul, 4.8. Mason Good, Stute, Mine. Danthez, and Thou ret have recorded cases in which the cord was entirely wanting.
A cord is short when there is not enough of it to permit the expulsion of the Loans without detachment of the placenta.
Devilliers has shown that the cord; when of normal length, and free, gives us more than sufficient length for the expulsion of the fcetus; but each band and knot lessens the amount of free play. In some cases ab solute shortness of the cord has been found coincident with certain defor mities, and Carus and Froebel claim that they bear the relation of cause and effect.