90 Modes of establishing the Groups or Series. [CHAP. iv. 



male children are to the female, in the long run, in about 

 the proportion of 106 to 100. Now if we were told that 

 there is nothing in this but &quot; the development of their re 

 spective probabilities,&quot; would there be anything in such a 

 statement but a somewhat pretentious re-statement of the 

 fact already asserted ? The probability is nothing but that 

 proportion, and is unquestionably in this case derived from 

 no other source but the statistics themselves; in the above 

 remark the attempt seems to be made to invert this process, 

 and to derive the sequence of events from the mere nume 

 rical statement of the proportions in which they occur. 



15. It will very likely be replied that by the proba 

 bility above mentioned is meant, not the mere numerical 

 proportion between the births, but some fact in our consti 

 tution upon which this proportion depends; that just as 

 there was a relation of equality between the two sides of the 

 penny, which produced the ultimate equality in the number 

 of heads and tails, so there may be something in our consti 

 tution or circumstances in the proportion of 106 to 100, 

 which produces the observed statistical result. When this 

 something, whatever it might be, was discovered, the ob 

 served numbers might be supposed capable of being deter 

 mined beforehand. Even if this were the case, however, it 

 must not be forgotten that there could hardly fail to be, in 

 combination with such causes, other concurrent conditions in 

 order to produce the ultimate result; just as besides the shape 

 of the penny, we had also to take into account the nature of 

 the randomness with which it was tossed. What these 

 may be, no one at present can undertake to say, for the best 

 physiologists seem indisposed to hazard even a guess upon 

 the subject 1 . But without going into particulars, one may 



1 An opinion prevailed rather at Quetelet amongst others) that the 

 one time (quoted and supported by relative ages of the parents had 



