180 



ancient animals. I have urged him in the strongest manner to publisli this 

 winter his new species. 



I have to thank you likewise for your kindness in sending me the fragment 

 of Obolus found by Dr. Otto Torrell in the old Swedish rocks. Unfortun- 

 ately it is but a fragment of a valve, and not complete enough for specific 

 identification. It has, however, interested me much, and should you have 

 occasion to write to Dr. Torell again, would you kindly let him know that 

 I should much desire to examine a good specimen of each species of the 

 Braehiopoda found in those old Swedish Primordial rocks. I have recently 

 worked out for Dr. Volborth of St. Petersburg all the species and genera of 

 Obolus, &c., found in the oldest Russian Primordial rocks, and it would be 

 most interesting to see if those Swedish forms agree with those found in 

 Russia and Great Britain. * * * With very many thanks for all your 



kindness, 



I remain, yours truly, 



THOS. DAVIDSON. 



The next letter is from Sir Charles Lyell, and is of interest if 

 only as shewing that though Harkness mainly confined his energy 

 to the working out of questions of a purely geological nature, the 

 bearing of collateral subjects on his favourite science were not by 

 any means overlooked. 



73 Harley Street, 25th November, 1868. 



My dear Harkness, 



I have been intending every day to thank you for your letter, when 

 another arrives alluding to the Spiranthes. In the first place I am pleased 

 to find that you are reading my book ; for although the sale is getting on 

 remarkably well, considering the dangerous experiment made of increasing 

 the size and cost, yet as it is only a new edition I cannot reasonably expect 

 those who have read the former version to find out how much novelty there 

 may be in this. Accordingly I find, as a general rule, that the older geolo- 

 gists are not aware that I have published anything new in these later times, 

 and I often wonder who are my readers. 



Seeing that Bentham in his "Handbook of the British Flora," 1858, 

 mentioned Splranthes gemmipara as a solitary instance of a species limited 

 to the British Isles, I relied upon his accuracy, for he says that Dr. 

 Lindley has shewn that the Irish plant had been erroneously referred to the 

 North American Splranthes cernua, a plant which it closely resembles. 



The question now is, whether your reference to Professor Reichenbach 

 corrects Lindley and Bentham. I shall consult the latter and Hooker. 

 And in the meantime I am much obliged to you for calling my attention to 

 this subject, and shall be glad of any other criticisms. 



