366 Harris Hawthorne Wilder 



cations if we could only study these types of monsters as early embryos. 

 Such material is^ however, all but impossible to obtain, but with the 

 gradually increasing use of the embryos of various vertebrates in general 

 laboratory work in colleges and universities, an increasingly large num- 

 ber is yearly sorted over, and thus the chance of such fortunate dis- 

 coveries is always on the increase. Embryo avian monsters are fre- 

 qiiently met with, but these, for the reasons above cited, are rather 

 unsatisfactory material for work, although Kaestner has turned these 

 very disadvantages into points of much significance and has obtained 

 therefrom highly important results. Early mammalian embryo mon- 

 sters, of the types referred to in this paper, are almost unknown, but 

 since in my collection I already have two of them, Terata III and XXX, 

 (see p. 369, foot-note; also Fig. 27) such research appears to be quite 

 within our reach. 



Aside from the obvious advantages of getting rid of secondary modi- 

 fications, the study of "teratembryology" offers another, which is very 

 great. Just as certain of the types which belong naturally in a terato- 

 logical series are bound during later development to meet with certain 

 mechanical difficulties which prevent them from surviving birth, the 

 so-called "non-viable" monsters, it is also very probable that others 

 which exist so far as we know only in a theoretical series actually begin 

 embryonic existence but meet with difficulties which set a term to their 

 life while still embryos. Such forms would then be expelled in a dis- 

 integrated condition, or absorbed, and would thus never come within 

 the ken of the teratologist. 



If now we may assume that there is a class of monsters which are 

 primarily as symmetrical in structure and as normal in their tissues as 

 are the beings we usually consider normal, and if we may hold that 

 they, as well as normal beings, owe their structure to some germinal 

 variation, there is great need of a distinct term, which is broad enough to 

 include both these forms of monsters which are merely deformities and 

 pathological cases. In defining this term a set of duplicate twins, 

 whether separate or conjoined, should have the value of a single unit. 



For such an organism (or set of organisms), whether normal or ab- 

 normal, whether less or more than or equivalent to a normal being, and 

 lastly whether perfect or deformed, provided the deformity is due to 

 a secondary cau^e as explained above, I propose the name Cos:\roBiON' 

 (plural CosmobiaJ^ an orderly living being. In this term, the mean- 

 ing of which exactly expresses my idea, the only violence to classic 



