PECULIARITIES OF THE FOSTUS. 277 



umbilical vein, like two small strings wound in this way upon a 

 larger one. Their diameter is from a line to a line and a half. 

 They anastomose as they join the placenta, but not previously. 



Like the circulation between arteries and veins in other 

 parts of the body, the capillaries of the umbilical arteries termi- 

 nate in those of the i mbilical vein in the placenta. From the 

 observations of Wrisberg, Osiander, and the highly distinguished 

 Professor Chapman of the University of Pennsylvania, it seems 

 that there is no direct vascular communication between the mo- 

 ther and the foetus. 



This opinion is founded upon the leading facts, that the finest 

 injections do not pass from one to the other; that foetuses, after 

 the death of the mother from haemorrhage, still live and retain 

 their usual quantity of blood; that if the fetus be expelled entire 

 with the placenta, and membranes unhurt, the circulation still 

 continues. One example of which was witnessed nine minutes 

 by Wrisberg;* another fifteen by Osiander;f some from ten to 

 twenty minutes by Professor Chapman ;J another for an hour 

 by Professor Channing of Boston, and Dr. Selby of Tennessee,^ 

 where a bath of tepid water was used to resuscitate the foetus. 

 Also, from the observations of Breschet, it seems that the glo- 

 bules of the blood of the foetus, when inspected by the micro- 

 scope, are different in appearance from those of the mother.|| 



Mascagni says that he has made several most minute injec- 

 tions of the pregnant uterus, so as to cover with small vessels 

 its whole internal surface, and to return the injection by the ute- 

 rine veins: and yet he has never succeeded in injecting, in that 

 way, the secundines.lf 



I have, myself, repeatedly tried by minute injection to pass 

 articles from the fcetal into the maternal vessels, and the re- 

 verse, but always without success; in two instances, the experi- 

 ment was upon human subjects, and, in the others, on the cow. 

 In one of the latter, I perceived that some of the injecting mat- 

 ter thrown into the fetal vessels nad got into the uterine veins; 

 but as the observation was in opposition to all my other, and 



* Meckel, Man. D'Anat. vol. iii. p. 163. f Id. 



4. Chapman's Med. and Phys. Journal, vol. i. p. 6. Id. 



I Am. Med. Jour. vol. i. p. 193. J Prodromo, vol. i. p. 127- 

 VOL. II. 25 



