(68) To the title of the paragraph, Pander made a 

 footnote, in which he indicated that Malpighi saw the 

 rudiment of the embryo in a still non-incubated egg, and 

 at six hours of incubation-embryo with head. Pander did 

 not suspect the reliability of these observations, although 

 he presumed that there was erroneous determination of the 

 time of incubation here, because development could begin 

 before incubation (246) . 



(69) Haller had already described this transparent 

 field, as Pander noted in the footnote, and called it nidus 

 of the chicken (nidus pulli) . He indicated that it could 

 assume different forms (246) , 



(70) Pander considered that from the two layers, 

 described by Wolff, the external one was the yolk membrane, 

 and is referred to in the article "About development of 

 intestine" (Novi Comm. Acad. Petropol., V. 12, p. 415): 

 "There is no basis to consider, that it is related to the 

 self-cover of the embryo; it forms the common membrane 



of the yolk, in which the embryo and the amnion are also 

 included". Pander, apparently, made a mistake, because in 

 many places of the Wolff's article cited by him, Wolff spoke 

 sufficiently clearly about two layers, which were related to 

 the embryo itself and were present under the yolk membrane 

 (246). 



(71) Pander referred here to the description of the 

 early embryos by Tideman and Oken. The two latter authors 

 saw only a thread-like body of the embryo with a swollen 

 head end. Only Haller noticed "the split tail, widening at 

 the start and assuming the form of lancet at the end. These 

 halves of tail, obviously, correspond to the posterior ends 

 of Pander's primary folds (251). 



(72) Concerning the distribution of this legend, it 



is possible to judge, in particular, by the mentioned course 

 of physiology of Burdach. He spoke about the stages of the 

 study of the embryonic development and characterized the 

 two first epochs of history of embryology — the epoch from 

 Aristotle to Harvey and the epoch of Wolff. He wrote later 

 on: "The third epoch consisted of the works of Dol linger 

 and Pander, who, in many years, compiled investigations 



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