INHERITANCE OF VARIATES IN THE ARMADILLO 173 



Perhaps, however, the best evidence of the existence of alter- 

 native inheritance is found on the examination of the conditions 

 in individual offspring. The nearest approach to complete iden- 

 tity between one parent and an individual offspring is seen in 

 set C 95 in which fetus II has nine out of its ten rings identical 

 with those of the mother. There are several cases in which there is 

 complete identity for 8 rings, and still more for 7 rings, between 

 mother and individual offspring. Such cases are surely good 

 examples of a sort of dominance of the tendencies of one parent 

 over those of the other and are in that sense to be considered as 

 belonging to the category of characters inherited according to the 

 laws of alternative inheritance. 



COMPARATIVE STUDY OF THE INHERITANCE OF SCUTE AGGRE- 

 GATES IN THE FIVE MAIN ARMOR SHIELDS 



In order that the present study may be complete for the armor 

 it is necessary to bring in for comparison the data for the other 

 three shields, cephalic, scapular and pelvic. The labor involved 

 in counting the scutes in the two last named shields, which possess 

 an average of 2000 scutes to the individual, is so great that it is 

 necessary to limit the number of sets studied to 20, 10 of each sex. 

 These 20 sets were chosen solely on the basis of the size of the 

 fetuses, since it is necessary to use the most advanced stages in 

 order to obtain accurate counts in all regions. This is especially 

 true for the scapular and pelvic shields where the scutes are very 

 small and are not arranged regularly in rows. It is necessary to 

 mark with ink spots the scutes as enumerated and much time is 

 consumed in the process. The cephalic shield is the least favorable 

 for study on account of the fact that its scutes are not sharply 

 marked off from those of the face and nose. It is only by setting 

 up certain artificial boundary lines that one is able to secure even 

 a reasonably accurate comparison between parent and offspring. 

 So far as individuals of a set are concerned, however, this difficulty 

 is not serious, for one can readily decide before beginning the 

 process of counting whether or not certain doubtful border-line 

 scutes are to be included in the count. 



