I9I2.] 



ANALYZED BY THE MENDELIAN METHOD. 



179 



and six kinds of germ plasm matings, disregarding sex, are pos- 

 sible. These latter matings, together with the sort of offspring 

 they may be expected to yield, are as follows: 



I. Nulliplex X Nulliplex = lOO per cent. Nulliplex. 



n. Nulliplex X Simplex = 50 per cent. Nulliplex; 50 per cent. Simplex. 



HI. Simplex X Simplex = 25 per cent. Nulliplex; 50 per cent. Simplex; 



25 per cent. Duplex. 



IV. Nulliplex X Duplex = 100 per cent. Simplex. 



V. Simplex X Duplex = 50 per cent. Duplex ; 50 per cent. Simplex. 



VI. Duplex X Duplex = 100 per cent. Duplex. 



Practically, it is not always easy to distinguish the simplex from 



Fig. I. In the above chart both of the parents are epileptic. There were 

 four children from this mating, three of them were epileptic and the fourth, 

 after the chart was made, was discovered to be feeble-minded. This case is 

 of the type nulliplex X nulliplex. E, epileptic; F, feeble-minded; A, alco- 

 holic ; A'', normal. Case 3,667. 



the duplex condition, although frequently a simplex condition is 

 indicated by an intermediate mental status. 



The new method of obtaining the material is largely responsible 

 for any advance which has been made in the study of the inheritance 

 of epilepsy. 



The field workers visit the parents and other relatives of the 

 patient and interview them in their homes, where they are at ease, 

 and free from restraining influences, as would not be possible else- 

 where. The family physician, clergyman, school teacher and other 

 interested persons are also interviewed, for the purpose of securing 

 an accurate account of the mental status, environmental conditions, 



