ON PHOTOGRAPHIC RECORDS OF PEDIGREE STOCK. 599 



to breeders. They should be serviceable to them not only as portraits, but 

 also as affording means of obtaining measurements of the animal. It will 

 be shown that the system might be easily initiated, and be afterwards 

 self-supporting, but for the moment it will be convenient to take these 

 important conditions on trust, and to begin by considering what could be 

 done if we had the photographs. I will suppose, then, that the system 

 has been in successful operation for many years and that it has become 

 possible to obtain photographs of the parents, grandparents, and other 

 ance.stors of each of a large number of pure-bred horses and cattle taken 

 under specified conditions. We have to explain how such photographs 

 might be employed in improving the art of breeding. 



An habitual study of the form of each pure-bred animal in connection, 

 with the portraits of all its nearer ancestors would test current opinions 

 and decide between conflicting ones, and it could not fail to suggest new 

 ideas. Likenesses would be traced to prepotent ancestors and the amount 

 of their several prepotencies would be defined ; forms and features that 

 supplement one. another, or, as it is termed, 'nick in,' and others that 

 clash or combine awkwardly, would be observed and recorded : conclusions 

 which are based on incomplete and inaccurate memories of the appear- 

 ance of the several members of the ancestry would be superseded by others 

 derived from a study of their actual photographs. The value of the 

 ancestral law would be adequately tested, and it would be possible to 

 amend it where required. Thus the effects of organic stability, to which 

 I have often called attention, have yet to be dealt with if they are not in- 

 directly included in the law as it stands. Lastly, it is not unreasonable to 

 suppose that every important stallion or bull would have a pamphlet all 

 to himself, with photographs of his ancestors, and with appropriate par- 

 ticulars about each of them. Such pamphlets would become recognised 

 as a just form of advertisement. 



Composite Photography. — It may be said that, even if all the ancestral 

 photographs were spread in full view on a table, no human brain could 

 combine into a single mental image the peculiarities in feature even of the 

 two parents, and of the four grandparents, in the proportion laid down by 

 the ancestral law. There is, however, a method by which a substitute for 

 a mental picture may be obtained, which may possibly prove serviceable 

 in practice. It is by making composites of the photographs, allotting to 

 each portrait its appropriate time of exposure.' I submit a few compo- 

 sites which I have made of the heads of racehorses : the component por- 

 traits are from the earlier numbers of the ' Racing Illustrated.' I enlarged 

 them to an uniform scale, reckoning from the middle of the eyeball to the 

 fold within the nostril, cut them out to get rid of the confusion introduced 

 by a variety of background, and then combined them in various pro- 

 portions. Especially I took six, those of (A) Sir Visto, (B) Solaro, (C) 

 Raconteur, (D) St. Marnock, (E) Speedwell, and (E) Salebeia, which will 

 henceforth be distinguished by those letters. With the plate, stop, and the 

 two small electric lamps that I used for illumination, it required an expo- 

 sure of 240 seconds, say of 12 units of time, each consisting of 20 seconds, 

 to give a good copy of any one of the portraits, so I proceeded as follows : — 

 First, I made a composite of A and B, allowing G units of exposure to each 



> Composite Portraits, Nature, 1878; Composite Portraiture, Joum. FJiot. Soc, 

 1881. 



