THE MEASUREMENT OF VARIATION. 13 



Subsequently * he proved that a similar relationship 

 was true not only for the height, weight, strength, lon- 

 gevity, and other physical qualities of man, but also for 

 his intellectual and moral qualities, such as age at mar- 

 riage, age of criminals, and so on. He considered also 

 that these laws extend to the whole Animal and Vege- 

 table Kingdoms, though he did not give proofs of this 

 hypothesis. 



In confirmation and extension of Quetelet's results, 

 the observations of Mr. Francis Galton f may be 

 quoted. These were made at the Anthropometric 

 Laboratory of the International Health Exhibition of 

 1884, upon from 489 to 1788 men and women. It was 

 found that the variations in height, span of arms, 

 weight, breathing capacity, strength of pull, strength of 

 squeeze, swiftness of blow, and keenness of sight all con- 

 formed in their distribution to the Law of Error. With 

 regard to the lower animals, Professor Weldon has 

 made measurements on the carapace, post-spinous por- 

 tion of carapace, length of the sixth abdominal tergum, 

 and length of telson, in the case of two to five local races 

 of shrimps, and obtained a similar result. He has 

 also made no less than eleven different series of 

 measurements on 999 female crabs (Carcinus mcenas) 

 obtained from Plymouth Sound, and a similar number 

 on 999 specimens obtained from the Bay of Naples. 

 Twenty series of frequencies of deviation from the 

 average were thereby obtained, and were found in every 



* " Anthropometrie," p. 257, 1870. 

 f " Natural Inheritance," p. 201. 



t Proc. Roy. Soc., xlvii. p. 445, 1889, and Proc. Roy. Soc., li. p. 2, 

 1892. 

 Proc. Roy. Soc., liv. p. 318, 1893. 



