428 Harris Hawthorne Wilder 



a trace of magnesium chloride it may be that here also the germ 

 is secondarily modified and that the greater precision in the results 

 is due to the substitution of a chemical rather than a mechanical 

 force, that is, a molecular rather than a molar one. Since this 

 force is an extremely subtile and delicate one it is also possible 

 that the forming germ may be thus induced to alter its structure 

 from the beginning, and in this case the resulting organism would be 

 a true Cosmobion. 



Again, even though the monsters resulting from present or future 

 experiments, in which the cause is applied after the formation of 

 the germ and is therefore secondary, be found upon careful examina- 

 tion to be definite Cosmobia, it will prove only that such monsters 

 can be thus produced and not that Nature does produce them in the 

 same way. 

 6. This last paragraph may, perhaps, be added here, although it is 

 not so much a conclusion as a statement of position. I may first 

 emphasize that while I hold that the conception of CosmObia, as 

 given in paragraphs 1 to 3, is an established fact, and that in the 

 determination of anatomical parts of undeformed though abnormal 

 Cosmobia no greater difficulty is experienced than in the study of 

 normal beings, I wish to consider all that I have said concerning 

 causes (Paragraphs 4 and 5) to be in the form of an hypothesis, 

 about which I have no wish to be dogmatic. Secondly I wish to 

 urge farther experimentation, especially with external causes that 

 may affect the formation of the germ before and after fertilization, 

 since it is my strong belief that the natural causes of abnormal 

 Cosmobia are applied during this period. Finally it must be 

 remembered that results similar to those produced naturally may be 

 formed by means other than the ones Nature habitually uses, and 

 that even a definite experimentally produced monster may not in 

 itself furnish a proof that we have found the natural cause of such 

 an organism. A fairly good double (or doubled) monster may be 

 produced by grafting, but such a result is far from substantiating 

 the assertion that double monsters are produced by Nature in that 

 way. 



Literature. 



Although, with such comprehensive and modern text-books on Tera- 

 tology^ at hand as that of E. Schwalbe^ there is no longer any need of 

 accompanying individual papers on the subject with extensive biblio- 



