CHAPTER 6 



WOLFF'S TERATOLOGIC/! WORKS 



On publishing the work discussed above about the 

 development of the intestine, for which the main objective 

 was to establish the theory of epigenesis, Wolff never 

 considered his task accomplished. He always sought new 

 material for the question in which he was interested. 



The actual arguments against preformation and in favor 

 of epigenesis he drew from teratology, which he continued 

 studying extensively throughout his long years of work in 

 Petersburg. From Raikov's work it is clear that Wolff had 

 collected a large amount of material in which he investigated 

 in detail the structure of human monsters or malformations, 

 which, along with his theoretical judgments concerning a 

 number of general biological problems, were never prepared 

 for publication. 



In addition to human monstrosities, Wolff was interested 

 in the development of animal monstrosities, as evidenced by 

 his three publications on the subject. Two of them, "About 

 chicken monstrosities" and "Description of a double-headed 

 chicken," are included in the list of Wolff's printed works 

 attached to Raikov's book, although their inclusion in this 

 book is not highlighted, and a third, "A single egg carrying 

 twins," is not included in the list. These works of Wolff, 

 in Latin, remain almost unknown. Thus it becomes essential 

 to give a short account of their contents; moreover, 

 interesting factual data is in all of these works, and to 

 the second, the most commonly known, is attached on 

 independent report, "About the origin of monsters." 



Wolff's first published teratological work, his "A single 

 egg carrying twins''^ (Fig. 8 - 10), begins with the reminder 



1. Wolff, "Ovum simplex gemelliferum, " NOVI COMMENT. ACAD. 

 SCIENT. PETROPOLIT. v. XIV pro Anno MDCCLXIX, 1770, 

 pp. 456 - 483. 



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