No. 595] 



SHORTER ARTICLES AND DISCUSSION 



1 4:} 



warrant such a conclusion, as the present paper will attempt to 

 demonstrate. 



It is stated on page 120 of the article in question that the data 

 used in the paper are taken from the tables accompanying Har- 

 man's publication. Since we are concerned wholly with a ques- 

 tion of interpretation we may confine ourselves to these tables. 2 

 The families recorded in the tables arc classified by Jones and 

 Mason as follows (p. 120) : 



After discarding all the doubtful cases, and picking a sibship with its 

 parents from the table as a family, there is left a total of one hundred 

 and twenty-five families which are classified into three different cate- 

 gories, as follows: (A) Both parents normal with at least one abnormal 



congenital cataract, with at least one abnormal child; (C) both parents 

 abnormal, giving only abnormal children. 



In each of these groups (A,B,andC) it is thought that evidence 

 is found in support of their contention that congenital cataract 

 is a recessive character. "We may now consider this evidence in 

 the order in which it is presented. 



In group A, 31 families are cited in which both parents are 

 normal with one or more affected children. This is the strong- 

 est, or really the only, evidence that is offered in favor of the 



there are 16 in which the affected individuals produced no off- 

 spring or nothing but normals. We do not wish to lay great 

 emphasis on this point, but in such cases one should bear in mind 

 the common clinical belief and the experimental proof (for rab- 

 bits and guinea-pigs) 3 that a* certain number of congenital cat- 

 aracts are produced by intrauterine poisoning without necessarily 

 any reference to heredity. 



Another possible explanation for some of the examples in group 

 ^ is that they represent cases of origin de novo. Jones and 



moirs, XI, pp. 126-169. Pl.XXVIII-XXXIII. London, 1910. 



3 Pagensteeher, H. E. "Uber eine Methode der gemeinsamen experi- 



say: 



2 Harman, N. Bishop, "Congenital Catarac 

 tan Inheritance," Part IV, Section XIII 



