406 Duplicate Twins and Double Monsters 



5. Ritta-Christina, b. Sardinia, 1829. They " joined in a common trunk 

 at a point a little below the mammse." They died at an early age. 



e. Two separate and equal heads and necks upon a single trunk tohicJi is 

 normal, or with some duplication at the shoulders, and with a single pair of 

 arms. [In this especial care must be exercised to distinguish between cases 

 in which the two heads are equal, i. e., duplicates, and those in which one 

 appears as an outgrowth or " parasite " of the other. Only the first of these 

 belongs here, the other is not a case of true duplicates; in the one the com- 

 ponents are homodynamous, in the other heterodynamous.] 



Type: As there seems to be no recent case of a human monster of this 

 sort, we may take as 'a type the two-headed turtle described by Barbour, 88. 

 This is referred to also by Bateson, 94, who reprints Barbour's figure. This 

 phenomenon seems to be especially common in snakes. 



Other cases: 



1. Double-headed girl of 1G65; each head was baptized. It lived but a 



short time. 



2. Milanese girl (of about the same date). Two heads, but the rest appar- 



ently single; after death she was found to have two stomachs. 



(The numerous cases cited in which one head is described as ugly or 

 deformed are doubtless to be referred to II, below.) 



['A highly interesting case was dissected by Dr. Wenzel Gruber and figured 

 by him in his memoir of 1859. Externally it would belong in this subdivision, 

 but the skeleton displays two complete backbones, including coccyx;- between 

 which, in the sacral region there is a small spade-shaped piece representing 

 the rudiment of the of the two internal ossa innominata. 



The inner ribs are complete in number but strongly united, and there is a 

 small rudiment of the inner shoulder girdle. Gruber figures this under the 

 name " Thoracogastrodidymus, Case II"; his "Case I" of the same name 

 possesses a visible median arm rudiment, and has been described above under 

 ih).] 



f. Like the last tico, but loith the two compound heads incomplete and 

 united to one another. 



Type: Moreau's case; exhibited in Spain. Possessed a fused head, with 

 two noses and two mouths; each component had a perfect eye, the outer, 

 while the two inner eyes were represented by a poorly developed median eye, 

 with two pupils. 



Other cases: 



Buffon mentions a cat which was the exact counterpart of Moreau's case 

 (see also Forster, Taf. I, Fig. 1-6). 



A less marked class of defects, in which a single and otherwise normal 

 individual possesses a double tongue, double uvula, or other doubling in the 

 region of nose, mouth or throat, undoubtedly belongs here, and represents 

 the process of doubling in its inception. These must be carefully distin- 

 guished, however, from cases of cleft palate, harelip, etc., which are due to a 

 failure of perfectly normal parts to close in the median line, and which have 

 no relation whatever to the present subject. (Compare the note below under 

 diphallic terata (i) ). 



[Up to this point the cases cited are those in which the duplication becomes 

 gradually reduced below while the two components remain distinct above; 



