Manchester Memoirs, Vol. I. (1906), No. 11. 



XI. On the Difference between Physiological and 

 Statistical Laws of Heredity. 



By A. D. Darbishire, M.A. 



Demonstrator of Zoology in the Royal College of Science, London. 

 Received and read March 6th, igo6. 



Contents. 



1. Introductory. p. i. 



2. Statistical Laws. 



{a) Pearson's Law, p. 4. 



{b) Galton's Law. p. 4. 



{c) The difference between the two. p. 5. 



3. Physiological Laws. 



(a) The Law of Diminishing Individual Contribution. 



p. 8. 



(b) Mendel's Law. p. 11. 

 {c) The difference between the two. p. 14. 



4. The Difference between statistical and physiological 



Laws. 

 {a) The former " descriptive " : the latter " explan- 

 atory." p. 15. 



{b) Mendel's Law true of units : Pearson's of masses. 



p. 19. 



{c) Examples of the confusion between physiological 

 and statistical Laws. p. 23. 



{d) Description of a method of dealing with the 

 material of a breeding experiment in such a 

 way that the data obtained may be used to 

 test the validity both of Mendel's and of 

 Pearson's Law. p. 28. 



((?) Why do white sheep eat more than black ones ? 



P- 31- 



July 6th, igo6. 



