442 Mabel Bishop 



(1) In Teras XII. 



(a) Heart — Comparison with normal. 

 (h) Anterior Arteries — Comparison with normal. 

 X — Arteries of the outer sides of the two 



components. 

 XX — Arteries of the inner (median) sides 

 of the two components. 



(2) In Teras I — Eeserved for separate investigation. 



(3) In Teras XV. 



(a) Heart — Comparison with normal. 

 ( h ) Anterior Arteries — Comparison with normal. 

 X — x4.rteries of the outer sides of the two 



heads. 

 XX— Arteries of the inner (median) sides 

 of the two heads. 



(4) In Teras XX. 



(a) Heart — Comparison with normal. 

 (&) Anterior Arteries — Comparison with normal. 

 X — Arteries of the outer sides of the two 

 heads. 

 XX — Arteries of the inner (median) sides 

 of the two heads. 

 Y. Comparisons of the Heart and Anterior Arteries of the Cosmobia. 



(a) Teras XV with XII. 



(b) Teras XX with XV. 



VI. Speculations concerning the formation of the actual conditions 



in the Cosmobia. 

 VII. The establishment of a single cosmobiotic series between normal 

 individuals and duplicate twins. 



Teratological literature is prolific with descriptive investigations of 

 individual monsters, but prior to the present study very little has been 

 recorded of Comparisons of monsters.- While a record of single cases 



-Wenzel Gruber in 1815 cited certain differences of internal anatomy in two 

 cases of "Thoracogastrodidymus," but his comparisons were few in number 

 and very general. In 1901 R. H. Johnson compared "Axial Bifurcation" in 

 thirteen or more two-headed snakes. These and certain obvious comparisons 

 of siceletons, such as illustrated in well-known atlases, seem to be about all 

 the work that has been done in this line. 



