188 MISCELLANEA. [1874. 



medium] managed to get the two men on each side of him to 

 hold each other's hands, instead of his, and that he was thus 

 free to perform his antics. I am very glad that I issued my 

 ukase to you to attend. 



Yours affectionately, 



Ch. Darwin. 



[In the spring of this year (1874) he read a book which 

 gave him great pleasure and of which he often spoke with 

 admiration : — The ' Naturalist in Nicaragua/ by the late 

 Thomas Belt. Mr. Belt, whose untimely death may well be 

 deplored by naturalists, was by profession an Engineer, so 

 that all his admirable observations in natural history, in 

 Nicaragua and elsewhere, were the fruit of his leisure. The 

 book is direct and vivid in style and is full of description and 

 suggestive discussions. With reference to it my father 

 wrote to Sir J. D. Hooker : — 



11 Belt I have read, and I am delighted that you like it so 

 much ; it appears to me the best of all natural history 

 journals which have ever been published."] 



C. Darwin to the Marquis de Saporta. 



Down, May 30, 1874. 



Dear Sir, — I have been very neglectful in not having 

 sooner thanked you for your kindness in having sent me your 

 ' Etudes sur la Vegetation,' &c, and other memoirs. I have 

 read several of them with very great interest, and nothing can 

 be more important, in my opinion, than your evidence of the 

 extremely slow and gradual manner in which specific forms 

 change. I observe that M. A. De Candolle has lately quoted 

 you on this head versus Heer. I hope that you may be able 

 to throw light on the question whether such protean, or poly- 

 morphic forms, as those of Rubus, Hieracium, &c, at the 

 present day, are those which generate new species j as for 



