Vol. XXIX. July, 1915. No. i. 



BIOLOGICAL BULLETIN 



HEREDITY AND ORGANIC SYMMETRY IN ARMA- 

 DILLO QUADRUPLETS. 



I. MODES OF INHERITANCE OF BAND ANOMALIES. 



H. H. NEWMAN. 



INTRODUCTION. 



Since the winter of 1909, when I first secured and began the 

 study of advanced polyembryonic fetuses of the nine-banded 

 armadillo, I have been struck not only by the striking resem- 

 blances among the individuals of a set of quadruplets but also 

 by certain equally striking differences. It was early noted that 

 well defined anomalous arrangements of scutes in the armor 

 bands were sometimes repeated with closely similar detail in 

 tw T o or more fetuses, and were totally absent in others. Occa- 

 sionally all four fetuses of a set showed a highly localized anomaly, 

 but differed materially in the extent of the irregularity and in 

 its symmetrical relations. 



The full significance of these conditions did not dawn upon me, 

 however, until some years later, when a set of quadruplets was 

 obtained in which the band anomaly in question was found to be 

 present not only in all of the four fetuses but in the mother as 

 well. Previous to this time only a few anomalous sets had been 

 studied and these happened to have normal mothers, a circum- 

 stance which led to the belief that these characters were not 

 strictly inherited from parents but were merely predetermined 

 early in embryonic life before the separation of the four embryos 

 from the originally single embryonic vesicle. The finding of 

 one unequivocal case of the direct inheritance from the mother 

 of the anomalous character stimulated a new interest in the 

 problem and made it necessary to collect a large amount of new 



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