1858.] STRIPED HORSES. 469 



of the front legs, still more rarely a very faint transverse 

 shoulder-stripe like an ass. 



Is there any breed of Delamere forest ponies ? I have 

 found out little about ponies in these respects. Sir P. Eger- 

 ton has, I believe, some quite thoroughbred chestnut horses ; 

 have any of them the spinal stripe ? Mouse-coloured ponies, 

 or rather small horses, often have spinal and leg bars. So 

 have dun horses (by dun I mean real colour of cream mixed 

 with brown, bay, or chestnut). So have sometimes chestnuts, 

 but I have not yet got a case of spinal stripe in chestnut, race 

 horse, or in quite heavy cart-horse. Any fact of this nature 

 of such stripes in horses would be mos^ useful to me. There 

 is a parallel case in the legs of the donkey, and I have col- 

 lected some most curious cases of stripes appearing in va- 

 rious crossed equine animals. I have also a large mass of 

 parallel facts in the breeds of pigeons about the wing bars. 

 I suspect it will throw light on the colour of the primeval 

 horse. So do help me if occasion turns up. . . . My health 

 has been lately very bad from overwork, and on Tuesday I go 

 for a fortnight's hydropathy. My work is everlasting. Fare- 

 well. 



My dear Fox, I trust you are well. Farewell, 



C. Darwin. 



C Darwin to J. D. Hooker. 



Moor Park, Farnham [April 26th, 1858]. 



... I have just had the innermost cockles of my heart 

 rejoiced by a letter from Lyell. I said to him (or he to me) 

 that I believed from the character of the flora of the Azores, 

 that icebergs must have- been stranded there; and that I Ex- 

 pected erratic boulders would be detected embedded between 

 the upheaved lava-beds ; and I got Lyell to write to Hartung 

 to ask, and now H. says my question explains what had 

 astounded him, viz., large boulders (and some polished) of 

 mica-schist, quartz, sandstone, &c., some embedded, and some 

 40 and 50 feet above the level of the sea, so that he had 



