70 STUDIES IN THE EVOLUTION OF ANIMALS 



Considering the millions of Horses that are bred everywhere, 

 both in a domesticated and also in a semi-wild state, it is astonish- 

 ing how little reliable information there is on this particular 

 subject. As I said, from an evolutionary point of view this study 

 would be important, as the history of dappling in any individual 

 ought to tell some tale regarding descent. 



In absence of any recorded accurate information, I have had 

 to explore the Horses in the streets of London and elsewhere, in 

 the immense stables of carrying companies, in Horse-shows, etc. 

 Wherever I could see any deviation which I considered of some 

 importance, I made a note of it on the spot. 



Have you ever observed a ' dappled sky ' ? The maculations 

 of some dappled Horses, such as those of Fig. 37, are not unlike the 

 patches of cumulus clouds with jagged edges, as they are often 

 seen close to each other in a ' dappled ' sky, the intervening blue 

 sky corresponding with the network of dark grey between the 

 Horse-dapplings. Just as clouds are unstable, break up, and run 

 into each other, forming a uniform dense haze, so do the jag-margined 

 Horse-dapplings seem to change with age and from other causes. 

 The cloud-patches of the Horse often break up and deliquesce — to 

 continue the simile — as seen on the hind-quarters of Figs. 34 and 39. 



This I found, and have confirmed it hundreds of times in 

 omnibus Horses. After severe exertion in drawing a loaded 

 omnibus, the superficial veins of the flanks, shoulders, and legs 

 start out. On the flanks they form reticulations which, in dappled 

 or partially dappled Horses, coincide with the dark reticulations. 

 In self-coloured Horses, such as pure whites, pure bays, etc., only 

 the venous reticulations are seen. But whenever there is a fine pig- 

 mentary reticulation of a different colour from the general colour, 

 the two reticulations coincide — the venous and the pigmentary. 

 In freshly clipped Horses all this can be seen very plainly. 



