174 H - H - NEWMAN. 



and second that two sets of offspring, all normal and males, 

 were discarded because the shell of the mother in each case was 

 badly damaged. If these five sets of male quadruplets be added 

 the count would be practically even so far as sex goes, 73 females 

 and 72 males. Other collections, moreover, have show T n equal 

 numbers of male and female sets of quadruplets. 



I. Three Categories of Offspring. 



A survey of the 140 sets of quadruplets reveals that there are 

 three well-defined classes: 



(a) Those in which both mother and offspring have anomalies. 

 Of these there are 56 sets, 29 female and 27 male. 



(6) Those in which the mother is normal but the offspring 

 have anomalies. Of these there are 41 sets, of which 22 are female 

 and 19 male. 



(c) Those in which both mother and offspring are normal. Of 

 these there are 43 sets, of which 22 are female and 21 male. 



Unless the character in question is strongly inherited as a 

 dominant we would expect to find a fourth class composed of sets 

 in which the mother has an anomaly but all offspring are normal. 

 Only one such case occurs, and this is a doubtful one in which 

 the anomaly of the mother is a double scute that may be due to 

 the fusion of two scutes after a local injury. This doubtful 

 case has been included in class (c). Another case that I at first 

 thought was in this fourth class was found on examination to 

 belong to class (a), for one of the fetuses had a double scute in 

 the last scapular band which had been overlooked in the counts 

 because we were dealing only with the regular bands. The 

 facts of this case will be clear from an examination of Set C 65 

 (bottom of p. 187). 



The mode of inheritance of these anomalies does not appear 

 to be typically Mendelian, for, if the character is a dominant, 

 with the normal condition the recessive, we would expect a 

 considerable number of anomalous individuals to be heterozygous 

 for the character and to produce equal numbers of germ cells with 

 the anomaly factor and without it; so that on the basis of chance 

 mating we should often get normal offspring from the mating of 

 two heterozygous anomalous parents or from one heterozygous 



