6 Eugenics Record Office, Buli^etin No. 3 



^[p!d(N)(t)d)a)(t)[i]Ci](i][il(i] 



Chart VIII. M. E. S. Case No. 4455 



d Q .(l3 B (^ 6 tp]f(^ (p]d)6 ll][l]. [Ll(p)(^(N)6 

 (i) (£] (N] d) D (^ 15 |t| 



Chart IX. S. S. Case No. 15177 



(t [ii li li [i («) m d) a Q (^ ^ [3 



Chart X. D. H. Case No. 6699 



Gf® 



E ^ [^ 6 [P] (J] 6^ 



O d) (2) !z] [il Ctl (n] 



Chart XL C. R. S. Case No. 17242 



E Q S ^ (t). [t| 

 Chart XII. C. R. S.'s step-brothers and step-sisters. 



§ 3. Analysis of Pedigrees. — Let us now compare the propor- 

 tions of normal and neuropathic offspring which have resulted 

 from the different matings, as shown in the pedigree charts, with 

 the proportions of theoretical expectation. This will enable us 

 to determine whether or not the neuropathic make-up is actually- 

 transmitted in the manner of a recessive condition of a Mendelian 

 character. In other words, let us test, with the aid of our mate- 

 rial, the hypothesis that the neuropathic make-up is due to a lack 

 of a determiner in the germ plasm upon which the normal func- 

 tion of the nervous apparatus depends. 



We may consider the matings in the order of the six theo- 

 retical possibilities discussed in the first part of this paper. 



