HEREDITY AND ORGANIC SYMMETRY IN ARMADILLO. 3! 



These anomalies are strongly inherited but are subject to more 

 or less modification. Sometimes a band anomaly unilaterally 

 placed may be inherited unilaterally but with a reversed sym- 

 metry to that of the mother, or it may be bilateral. Sometimes 

 an extensive doubling is inherited both as a similar band doubling, 

 and as a single double scute in the individuals of a single poly- 

 embryonic set of offspring. Contrariwise a double scute in the 

 mother may be inherited as a more or less extensive unilateral 

 or bilateral band doubling. The peculiarity may also be re- 

 duplicated down the primary axis in two or more bands. 



Frequently in unilateral anomalies the different fetuses of a 

 set show reversed symmetry or mirror-imaging, but it is even 

 more common to find the unilateral anomaly on the same side 

 of most of the individuals, or bilaterally in one or more of them. 



In a number of cases the anomalies in different fetuses of a 

 set are so strikingly identical as to indicate a rigid predetermina- 

 tion of the details of the character, but in other cases there 

 appears to be only a predetermination of a generalized anomaly 

 that expresses itself to a greater or less extent in the various 

 embryos. In terms of Mendelian inheritance we may say that 

 an anomaly factor is inherited as a dominant character, but its 

 distribution among the fetuses of a set and its location and 

 extent are due to varying ontogenetic or epigenetic factors. 



The distribution of these inherited anomalies among the 

 various fetuses of the sets furnishes much interesting data, which, 

 together with data on the inheritance of double scutes, to be 

 presented subsequently, furnishes the basis of a discussion of 

 several general questions and especially those involved in the 

 concept of organic symmetry. 



This subject is reserved for a subsequent paper of the present 

 series. 



BIBLIOGRAPHY. 



Newman, H. H. and Patterson, J. T. 



'09 A Case of Normal Identical Quadruplets in the Nine-banded Armadillo 

 and Its Bearings on the Problems of Identical Twins and of Sex Deter- 

 mination. BIOL. BULLETIN, Vol. 17, No. 3. 



'10 The Development of the Nine-banded Armadillo from the Primitive Streak 

 Stage to Birth; with Especial Reference to the Question of Specific Poly- 

 embryony. Journal Morphology, Vol. 21, No. 3. 



