work, his capability as an extraordinarily thorough 

 investigator and acute ohseryer is recognized. He also 

 undertook more theoretical investigations, as seen in articles 

 on the yertebral origin* of the skull and in his academic 

 lectures, particularly in his introduction to comparative 

 anatomy. In this last work, he discussed ideas on the 

 reciprocal relationship of organisms. This gave B. E. Raikov 

 the basis for including Bo j anus in the list of Russian 

 evolutionists and forerunners of Darwin. (65) 



Bo janus 1 embryological work considered the embryonic 

 membranes and embryonic organs of the vertebrate animals, 

 mainly mammals. His first work, accomplished in 1813 and 

 published in 1815,3 was entitled "On the Fetal Membranes of 

 Dogs, Mainly concerning the Allantoic Membrane." The author 

 sought to address the unclear question of whether the amnion 

 was surrounded from all sides by the allantois. He effected 

 detailed and accurate description of canine fetal membranes 

 by applying a method of opening which guaranteed the membranes' 

 completeness and retained their normal location. 



According to Bo janus, the fetus extracted from the uterus 

 with its membranes has a cylindrical shape and is covered on 

 all sides by the chorion, in the middle, above the surface 

 of the chorion, a dominant zone of thicker fibrous vascular 

 tissue is limited by a fold-like border. This zone, which is 

 near the internal surface of the uterus, is in contact with 

 the maternal placenta. If an opening is carefully cut in the 

 chorion, the fetal fluid does not escape, and consequently its 

 receptacle remains intact. 



3. L. Bo janus, "De foetus canini velamentis imprimis de ipsius 

 membrana allantoide , " MEM. ACAD. SCI. ST. PETERSB . , 

 5 (1815) , p. 3021. This work was later published in German 

 (with indication to the original place of publication) in 

 the journal edited by L. Oken. At the beginning, in the form 

 of a short abstract, was a review of a number of comparative 

 anatomical works. "Verzeichnis meiner Arbeiten in der 

 vergleichenden Anatomie," ISIS, 7 (1817), pp. 876 - 884, 

 attached to the article, L. Bo janus, "Anatomie des 

 Blutegels," ibid., pp. 874 - 876, and then in detail: 

 L. Bo janus, "Abhandlungen uber die Hilllen des Hundefoetus, 

 insbesondere uber dessen Allantoides, " ibid . , 10 (1818), 

 pp. 1616 - 1623. 



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