TFIE ZOOLOGICAL STATION AT NAPLES. 597 



A. Botlie . . . Vergleichende Untersuchungen iiber die Function des 



Centralnervensystems der Arthropoden. ' Archiv. f. d. 



ges. Physiologic,' Bd. 6b, 181)7. 

 P. S. Monticelli . . Dictiomyxa Trinchesii g. sp. n. di Rizopode marine. 



' Boll. Soc. Nat., Napoli,' vol. 11, 1897. 

 C Child .... A Preliminary Account of the Cleavage of Arenicola cris- 



tata, with Remarks on the Mosaic Theory. ' Zool. 



Bulletin Univ. Chicago,' vol. 1, 1897. 



I 



PhotograjpMc Records of Pedigree Stock. 

 By Francis Galton, B.G.L. {Oxf.), Hon. Sc.D.(Camb.), F.B.S. 



[Plate IV]. 



It is my purpose shortly to communicate with the Councils of some of the 

 Societies who publish stud or herd books, urging the systematic collection 

 of photographs of pedigree stock and of more information about them 

 than is now procurable. Believing that if my proposals were carried into 

 effect, they would greatly facilitate the study of heredity, I desire, before 

 approaching the Societies, to submit my intended proposals to the criticism 

 of a scientific body, and none seems more appropriate for the purpose 

 than the Zoological Section of the British Association. 



The following remarks are based on the Ancestral Law, which will be 

 explained. Its purport is to measure the importance to the breeder of 

 taking into account the various members of the ancestry of the animals 

 he proposes to mate together, so much of the heritage coming on the 

 average from each of them. Then the methods of utilising this bulky 

 knowledge will be discussed, that of composite portraiture being one 

 means of dealing with numerous photographs ; another way is by obtain- 

 ing measures, which can be arithmetically combined, from the photographs 

 themselves, provided they have been taken in accordance with certain 

 simple instructions. Next, the plan will be explained by which the 

 Societies referred to above might initiate and maintain a systematic col- 

 lection of photographs and other information useful to breeders, which 

 should become self-supporting. Lastly, an allusion will be made to the 

 huge waste of opportunities of advancing the art of breeding that goes on 

 unchecked. 



Tlie Ancestral Laic. — I have lately shown how the general knowledge 

 that offspi-ing can inherit peculiarities from the various members of their 

 ancestry as well as from their parents may be superseded by a definite la-w 

 whose nature was first suggested to me by theoretical considerations. 

 Being subsequently in a position to verify its accordance with a large 

 number of pertinent facts, I submitted the results to the Royal Society in 

 a communication entitled ' On the Average Contribution of each Several 

 Ancestor to the Total Heritage of the Offspring.' ' My theory was 

 thoroughly examined from fresh points of view by Professor Karl Pearson, 

 F.R.S., in one of his remarkable ' Contributions to the Mathematical 

 Theory of Evolution,' - in which he showed that the theory accorded with 

 other observations, and accounted for other conclusions that had already 

 been reached. Assuming, then, that the Ancestral Law may be accepted 



» Proc. Ha/jj. Soc, 1897. - Ibid., 1898. 



