i6 TABOO AND GENETICS 



great, to give a good deal of justifiable 

 assurance. 



If we use our general biological evidence in 

 this way, merely to help in clearing up points 

 about human biology, we need not be entirely 

 limited to mammals. Some sex phenomena are 

 quite general, and may be drawn from the 

 sexual species most convenient to study and 

 control in experiments. When we get away from 

 mammalian forms, however, we must be very 

 sure that the cases used for illustrations are of 

 general application, are similar in respect to 

 the points compared, or that any vital differences 

 are understood and conscientiously pointed out. 



Too much stress cannot be laid upon the point 

 that such animal data, carefully checked up 

 with the human material, cannot safely be used 

 for any other purpose than to discover what the 

 facts are about the human body. When the 

 discussion of human social institutions is taken 

 up in Part II, the obvious assumption will 

 always be that these rest upon human biology, 

 and that we must not let our minds wander into 

 vague analogies concerning birds, spiders or 

 Crustacea. 



BIBLIOGRAPHY FOR CHAPTER I 



I. Loeb, Jacques. Artificial Parthenogenesis and Fer- 

 tilization. Chicago, 1913. 



