THE FORMATION (JF A ])EAP VAlilF/PY OF THE lurjIAN RACE. 203 



of their lives, ma ice tiicir iipiicaiauce in iiistitutii)iis for tiie deaf and diiinl), and fVoni tlu^ institution 

 records migbt l)e obtained tlu'ir names and addresses. Sueli ei)nsideratii>ns as tlie above led nie 

 to send to all tlie institutions in tUe country a circular letter of incjuiry reiiuestinj? tiie names and 

 addresses of all tlu! pupils who had been adniitteil wlio had deaf mute parents, and returns have 

 been received from a number of institutions.* 



A startiu<>- point has thus been gained for a new investij^ation of tiie sub'n'ct. The cases re 

 turned are sufficient in number to throw some light n[)on the pro|)ortion of deaf otfsprini;' Ixnn to 

 deaf mutes as compared with the proportion born to the comiiiunity at large. The total nund)er 

 of deaf-mutes in the country, according to the recent census, is .>.'!, S7S, wliicli gives us a pro[)ortion 

 of one deaf mute for every 1,.J00 of the i)o;mlation. If, then, tlie proportion of deaf mutes, origi- 

 uating among the deaf mutes them.selves, were no greater than in tlie community at large, they 

 should constitute only 1 in 1,.500 of the deaf-mute populatijn. lu other words, we should not 

 have more thau 23 deaf-mutes in the United States who are tlieinselvcs the chil.lreu of deaf-mutes. 

 The returns received from the institutions, however, show that no less thau 2L5 sucli children hare 

 already been admitted as pupils into .'io of the .^8 institutions of the country ('13 institutions not re- 

 plying to my «iueries). Pufiils are rarely admitted before they are 10 or 113 years of age and many 

 do not reach the institution until they are much older. Hence it is evident tli.at this number does 

 not at all express tlie total number of such cases in the United States. Even if we siiiiiiose that no 

 more thau 230 sucb cases are to be found in the country, the proportion is ten times greater than in 

 the community at large, or 1 in 150. But when we consider that nearly all of these children were 

 born deaf, whereas nearly half of the deaf mutes of the country (45.9 per cent.) became deaf from 

 accidental causes, we realize that the liability to the production of coiu/cnital deaf-mutes is more 

 nearly twenty times that of the population at large than ten times. It is evident that whatever 

 may be the actual number of deaf-mutes in the country who have one or both parents deaf, the true 

 number is much greater than that assumed above. From which it follows that the liability to the 

 production of deaf offspring is also greater. While, then, we cannot at present arrive at any per. 

 centage, it is certain that the proportion of deaf-mute offsprimj born to deaf-mutes is many times greater 

 than the proportion horn to the people at large. 



* See Tables S, T, U, aud W of the Apin'iulix. My best thanks are due to tlie principals aud snperinteudeuls for 

 their assistance iu this investigation. 



