I9II 



A. J. ROSANOFF AND FLORENCE I. ORR 



227 



rial, namely, the cases of matings from which no neuropathic 

 offspring have resulted. 



On the whole, no pretension is made here of total elimination 

 of error ; but we believe that whatever errors remain they are not 

 sufficient to invalidate the material as a basis for our study. 



§ 3. Statistical Analysis of Material. 



In the Preliminary Report, to which we have already referred 

 and which was based upon an analysis of the pedigrees of twelve 

 families, it was shown that the neuropathic constitution is trans- 

 mitted by heredity probably in the manner of a trait which is, in 

 the Mendelian sense, recessive to the normal condition. 



Sixty other families have since been investigated ; the entire 

 material now includes the pedigrees of seventy-two families, 

 representing two hundred and six different matings, with a total 

 of one thousand and ninety-seven offspring. In Table II this 

 mass of data has been arranged so as to show the proportions of 

 normal and neuropathic offspring which resulted from the various 

 types of mating alongside of figures representing theoretical ex- 

 pectation according to the Mendelian theory. 



TABLE Tl. 



Types of mating. 



Normal off- 

 spring. 



■3 i* 





o. KR X RRoo RR 



b. DRX RR 00 DR + RR 



bi. 



c. DD X RR* DR 



d. DRXDRaoDD + 2DR + RR 

 di. 



e. DD X DRoo DD+ DR 



/. DD X DDco DD 



Totals....' 



14 



10 



85 

 154 



45 



21 

 194 



77 

 







84Vj 

 130 



46 



21^ 

 219% 



77 

 



678 



Some of the data represented in the table require special 

 explanation. 



Among the offspring which resulted from matings of the first 

 type, RRxRR, ten are recorded as being normal, although 



