RESPIRA TION OF THE FCETUS. 731 



(oxygen) and carry it to the foetus ; at the same time, he recognises that the 

 foetus obtains its supply of nutrition in a similar manner. This view of the 

 foetal respiration was adopted and extended by Hulse, 1 and by Ray, 2 who 

 states his view in the following words : " The maternal blood which flows to 

 the cotyledons, and encircles the papillae, communicates by them to the blood 

 of the foetus the air wherewith itself is impregnate ; as the water flowing 

 about the carneous radii of the fish's gills doth the air that is lodged therein to 

 them." Mayow's brilliant work was allowed to drop into obscurity, and the 

 respiration of the foetus was not understood again until the beginning of this 

 century. 



Some physiologists, and among them Leclarc 3 and Geoffroy St. Hilaire, 4 

 maintained that the liquor amnii served the purpose of respiration by the skin 

 of the foetus. Haller, 5 Hunter, Osiander, 7 Autenrieth and Schlitz, 8 Emmert, 9 

 Joh. Miiller, 10 and E. H. Weber 11 stated that no difference could be observed 

 in the colour of the blood of the umbilical arteries and vein ; on the other 

 hand, Scheel, 12 Herissant and Diest, 13 Baudelocque, 14 Joerg, 15 Jeffray, 10 and 

 Bostock 17 noticed that the blood going from the placenta to the foetus was 

 of a more arterial hue than that going in the opposite direction, although 

 there was naturally not so marked a distinction as between the arterial and 

 venous blood of the adult. 



Even as late as 1840 the respiration of the foetus was not under- 

 stood, for Joh. Miiller, 18 the chief physiologist of the time, held that 

 plasma from the mother passed to the foetus, and so supplied the place 

 of respiration. Bischoff 19 looked upon the placenta as an organ of the 

 mother, and denied the existence of any special respiration ; this view 

 was contested by Litzmann, 20 who held that the foetus respired by the 

 placenta. Gradually, owing in a great measure to the work of Schwartz, 21 

 Gusserow, 22 and Schultze, 23 the truth discovered by Mayow in 1674 was 

 re-established, and received a final proof when Zweifel, 24 following the 

 suggestion of Hoppe-Seyler, showed in 1876 that the spectrum of 

 oxyha^moglobin could be clearly seen in the umbilical cord before the 

 child breathed by its lungs ; that, by taking the precaution to open the 

 uterus of a pregnant rabbit in warm normal saline solution, and thus 



1 Quoted from Ray's book, p. 73. 



2 "The Wisdom of God in the Creation," 12th edition, 1759, p. 74. 



34367 Quoted from Miiller, "Elements of Physiology," Baly's transL, 1838, vol. i. 

 pp. 317, 320. 



8 "Experimental circa ealorem fetus sangninem ipsius instituta," Tubings, 1799. 



9 Arch, f. d. Physiol., Halle, 1811, Bd. x. S. 122. 



10 ''De respiratione foetus," Lipsire, 1823, S. 10; " Handbuch der Physiologic," 1840, 

 Bd. ii. S. 729. 



11 Hildebrandt's "Anatomic," Bd. iv. S. 524. 



12 " De liquoris amnii aspene arteriae fcfttuum humanoruni natura et usu," Hafnipe, 

 1799. 



13 Haller's " Disputationes," vol. v. pp. 516, 526. 



14 Bichat's "Anatomic generale," tome ii. p. 465. 



15 "Die Zeugung," Leipzig, 1815, S. 273. 

 10 "De Placenta." 



17 "Physiology," London, 1828, 2nd edition, vol. ii. p. 199. 



" Handbuch der Physiologie," 1840, Bd. ii. S. 729. His words are : " Die von den 

 Blutgefassen angezogenen Safte dringen sodann direct ins Blut des Fb'tus. Durch diese Art 

 von Wechselwirkung mit miitterlichen Saften ist bei dem Foetus auch das Athmen ersetzt 

 oder ein ^Equivalent dafiir gegeben." 



" Entwickelungsgeschichte der Saugethiere und des Menschen," 1842, S. 541. 



"Ueber die Schwangerschaft," Wagner's "Handworterbuch." 



21 " Die vorzeitigen Athembewegungen," Leipzig, 1858. 



22 Arch. f. Gynaek., Berlin, Bd. iii. 



2y Jenaische Ztschr. f. Med. u. Xatunr., Leipzig, Bd. iv. 

 24 Arch.f. Gynaek., Berlin, 1876, Bd. ix. S. 291. 



