ORGANIC SYMMETRY IN ARMADILLO QUADRUPLETS. 



anomalous parent pairing with a normal parent. That we do not 

 find this condition means that we have evidently a non-Mendelian 

 result due probably to factor segregation among the quadruplets, 

 a process that must evidently take place in order to produce 

 sets in which some individuals are anomalous and some are 

 normal. This segregation must also affect the germ cells, so 

 that an individual that has an anomaly has also germ cells of 

 only one kind and these homozygous for the anomaly factor. 

 The same kind of mechanism that quite evidently segregates the 

 somatic anomaly factor must also be conceived of as responsible 

 for a segregation of the germinal anomaly factor. The results 

 do not appear to bear any other interpretation. Further dis- 

 cussion of this point follows the presentation of data. 



Since these anomalies are invariably inherited when present 

 in the mother we are driven to the conclusion that all these sets 

 in class (6), which have anomalies, but whose mothers are normal, 

 must have inherited their anomalies from the father. Further- 

 more, it is equally obvious that a considerable proportion of 

 those sets in class (a) must have anomalous fathers as well as 

 anomalous mothers. Thus class (a) is heterogeneous in that 

 it is composed of sets inheriting from both parents, on the one 

 hand, and from the mother alone, on the other. 



A calculation may readily be made of the relative sizes of the 

 various classes of offspring that should result if chance mating 

 occurs between anomalous and normal individuals. It will be 

 noted that 56 of the 140 mothers (or 40 per cent.) have anomalies. 

 Again 115 individual female offspring, or 39+ per cent, and 

 ill individual male offspring or 41+ per cent., have anomalies. 

 So we may be safe then in assuming that 40 per cent, of the in- 

 dividuals of the species have anomalies and 60 per cent, have 

 none. If 140 chance matings on this basis occur we should expect 

 the following classes: 



(a) 1 6 per cent, or 22.4 with both parents anomalous. 

 (a'} 24 per cent, or 33.6 with mother only anomalous. 



(b) 24 per cent, or 33.6 with father only anomalous. 



(c) 36 per cent, or 50.4 with neither parent anomalous. 

 The sum of classes (a) and (a') is 56, which is exactly the number 

 of sets in the observed class (a). 



