No. 637] 



IMMUNE SERA 



opmeiit, liowever— the relation of lens, (.ptii- cii]) and 

 choroid fissure— the defects are probably all aUriI)uiable 

 to the early injury of the lens. In some cases, both 

 among originals and descendants, an eye microphthalmic 

 at birth may undergo further degeneration such as col- 

 lapse of the ball and what appears to be a resorption as 

 if some solvent were operating upon it. The eyes of the 

 mothers apparently remained unaffected. This is prob- 

 ably due to the fact that the lens tissue of the adult rab- 

 bit is largely avascular and therefore did not come into 

 contact with the injected antibodies. 



That the changes in the eyes of the fetuses resulted 

 from the action of lens antibodies is indicated by the fact 

 that in not one of the forty-eight controls obtained from 

 mothers which had been treated with unsensitized fowl- 

 serum or with fowl-serum sensitized to rabbit tissue 

 other than lens, was there evidence of eye-defects, and I 

 may add, that among the hundred or more young ob- 

 tained later from mothers which were being experimented 

 upon with various types of sera or protein extracts, for 

 other purposes, not a single case of eye-defect has ap- 

 )oared. 



As already stated, once the anomaly is secured it may 

 be transmitted to subsequent generations through breed- 

 ing. So far we have succeeded in passing it to the eighth 

 generation without any other than the original treat- 

 ment. The imperfection, indeed, tends to become worse 

 in succeeding generations and also to occur in a propor- 

 tionately greater number of young. Though not anal- 

 yzed completely as to its exact mode of inheritance, it 

 has in general the characteristics of a Mendelian reces- 

 sive. Like such anomalies as bracliydactyly or Poly- 

 dactyly in man, the transmission is not infrequently of 

 an irregular, unilateral type, sometimes only the right, 

 at others only the left eye showing the defect. In the 

 later generations, probably in some measure as the result 

 of selective breeding, there is an increasing number of 

 young which have both eyes affected. 



