outside the embryo) . There is also an explanation of fetal 

 development; hence the changes of the individual organ systems 

 were followed. The dissertation mentioned that many systems of 

 the growing embryo had not been investigated by previous 

 authors, especially the muscular, circulatory, and nervous 

 systems. On the development of the skeleton, there was an 

 earlier book by Haller. With regard to the internal organs, 

 Tredern noted that many authors had thoroughly studied heart 

 development; other organs were investigated with more or less 

 detail, but he found no data about some, such as the fibrous 

 sac, uropygial glands, and the pancreas. Tredern sought to 

 correct mistakes and to fill gaps in his predecessors' 

 investigations. He modestly observed that his beginning should 

 receive support through verification by other scientists. 



V. THE CHICKEN AFTER HATCHING FROM THE EGG. Here he 

 mentioned only a few areas subjected to study, such as the 

 disappearance of the yolk and the yolk duct. 



VI. This division was entitled "Notes about Books," and was 

 composed of explanatory notes on the list of works on 

 embryology and related questions in the Gottingen library. 



The above list of problems represented such an extensive 

 plan of work that, according to Baer, no individual could 

 have accomplished it without achieving immortality. "This 

 report," Baer continued, 



occupies four pages (of sixteen) , and inevitably the 

 suspicion creeps in that the author gave only the list 

 of what he planned to investigate. But later he provided 

 accurate descriptions and defined observations with 

 abundant references to his predecessors, indicating 

 that the author knew the literature of his subject 

 completely. The references include K. F. Wolff's work 

 on the intestines, which almost nobody had known until 

 Meckel made his well-known German translation in 1812. 

 The same observations in Tredern 's dissertation are 

 stated very briefly and accurately, which requires us 

 to acknowledge the author's unquestionable talent in 

 minute anatomical investigations. An outstanding feature 

 is a table engraved on brass (Figure 18) . It is very 

 simple, almost just outlines, but in accuracy and 

 richness of detail it surpasses the brevity of the 



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