21 8 HARRIS HAWTHORNE WILDER. 



third interdigital pattern, is also due to the presence of a "lower 

 triradius" between the third and fourth interdigital areas, thus 

 rounding the proximal ridges of both into loops. The two proxi- 

 mal triradii shown in the print may be on the other feet as well, 

 placed beyond the limit of the actual print, and of this explanation 

 for the outer one, D, we can be certain, as it is never wanting, but 

 occasionally beyond the limit of the tread-area. The other, 

 closing the third area distally, looks like a departure from the 

 other three soles, thus making the total aberrancy of this foot 

 due to the presence of three separate triradii, which are wanting 

 in the other three. 



Summarizing the results of this investigation we have, in all 

 four hands, and in three of the feet, the typical correspondences 

 found only in true duplicates, also the right and left correspond- 

 ence usual in such cases. That these two individuals are really 

 duplicates there is no possibility of doubt since, in addition to the 

 close facial resemblance, which is typical, and the sex, which is 

 female, the commoner sex for duplicates, they were monochorial 

 and had a double, bilobed placenta. As I was fortunate enough 

 to be on the spot at the time of the birth, I secured the afterbirth, 

 which had been preserved with great care by the attending phy- 

 sicians. There was a single chorion, without trace of a separating 

 partition, and the placenta was bilobed, and nearly as large as 

 two normal placenta?. The umbilical cord was a single one for 

 1 1 cm. from the placenta, and proceeded from the margin, at the 

 point of bilobing, that is, at the notch between the two halves. 



This common cord contained the usual two arteries and a single 

 median vein, and at the forking of the cord to supply the two 

 umbilici the vein split into two branches, so that one of the arteries 

 and one branch of the vein continued into each individual cord. 

 The cord supplying Margaret, now and always the heavier infant, 

 was ii cm. long from the fork to the ligature; that supplying 

 Mary was 6. Margaret's cord was also somewhat greater in 

 caliber. Assuming that the ligatures were made in both cases 

 at about the same point these latter figures have a meaning, 

 otherwise they are of little value. 



We have thus a conjoined pair of true duplicate twins, mono- 

 chorial, monosexual, and with striking facial similarity. The 



