Monster of the SJieep Genus. 325 



Art. IV. Account of a monstrous Production of the Sheep Genus, 

 By John Chichester, Esq. M.D. 



Sir, 



In the course of the spring of 1827, I was requested by 

 Mr. Averill, a surgeon of distinction, settled in this place, and 

 well known to the profession by his treatise on operativ^ur- 

 gery, to assist him in the examination of a monstrous produc- 

 tion of the sheep genus (OSis Lin,), We were aware that, 

 by the means of injection, we should be most likely to discover 

 such facts as might be brought to bear upon the science of 

 organisation; but, besides some other unfavourable circum- 

 stances, putrefaction had too far advanced to admit of its being 

 minutely executed ; in which way only, perhaps, can the inves- 

 tigation of the law which governs those anomalies be success- 

 fully conducted. 



The great difference in the opinions which prevail at pre- 

 sent respecting monsters, comes, in all probability, from an 

 insufficiency of facts, or, rather, from an imperfect detail of 

 them ; since the greater part of the many cases to be found in 

 books, scarcely furnishes one probable induction, so loosely an4 

 indistinctly are they stated. Their philosophical history is 

 still in its cradle. 



The strange and irregular production of nature which at 

 present engages our attention, had only one head, which was 

 of the natural size, and complete in all its parts. It cannot be 

 regarded as being acephalous, in respect to one of the two 

 bodies, for the head was equally in common to both. 



There was one atlas only, of regular form, but somewhat 

 larger than natural. This circumstance, together with one 

 complete head, without the least rudimentary trace of a second, 

 is sufficient to exclude all idea of absorption having played any 

 part in this monstrous production ; while, on the other hand, 

 it favours very strongly the opinion of Blumenbach, Meckel, 

 and Geoffroy St. Hilaire, who lay it down as an axiom, that 

 all monstrosities (called by the latter les anomalies connees) are 

 the result of interrupted developement. 



The second vertebra was single at the upper part, with only 

 two articular surfaces, and of a size corresponding with the 

 bone above it ; below it was double, and, consequently, bad a 

 breadth somewhat out of proportion to its superior part. 

 Hence went off two distinct vertebral columns, both con- 

 taining the usual number of vertebrae in each division, and 

 each of them seemed perfect, to the very caudal extremities. 

 We found the whole of the other bones complete in number, 

 as well as form, throughout both skeletons. 



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