IN-AND-IN BREEDING. 183 



in which the statistics were collected, is noticed by Dr. 

 Bemis, who says : " But while indorsing the truthful- 

 ness of these statistics, it is my duty to state that those 

 which relate to marriages of consanguinity should prob- 

 ably not be received as a completely true representa- 

 tion of the results of such marriages ; some modifica- 

 tion of the mean of results might occur if the statis- 

 tics of all instances of in-and-in marrying, in the Union, 

 for example, could be comprised in one report. It is 

 natural for contributors to overlook many of the more 

 fortunate results of family intermarriage, and furnish 

 those followed by defective offspring or sterility. The 

 mere existence of either of these conditions would 

 prompt inquiry, while the favorable cases might pass 

 unnoticed." 



It is well known that the defects in question may 

 be produced by a variety of causes, but their presence 

 or absence in the cases reported is not noticed. 



When a predisposition to these or similar defects 

 exists in a family, the intermarriage of its members 

 would, without doubt, result in their repetition in the 

 offspring by direct transmission, and the influence of 

 the relationship of the parents could not, as a matter 

 of course, be determined. 



In nearly all the cases collected by Dr. Bemis, the 

 history of the ancestors of the parents is not given, 

 and there is therefore nothing to show that the defec- 

 tive children in the cases reported have not been af- 

 flicted by a direct inheritance of their deformity. In 

 one hundred and eighty-one of the cases, one or both 

 parents are reported as delicate in constitution, addict- 

 ed to bad habits, or suffering from disease, and in over 



