In view of his statement touching this pretended admission on my part, 

 and of his former one made upon mere hearsay, which in his opinion is 

 of no moment, I commend to Mr. D.'s consideration the following apposite 

 quotation from a daily paper, alluding to charges affecting the character 

 of another. " The hardihood and guilt of the assertion are equally great, 

 by all codes of ethics, whether a man asserts what he knows to be false, or 

 asserts what he does not know to be true." I apprehend that Mr. D. is 

 very close to both horns of the dilemma. 



See also Mr. D.'s foot-note to p. 131. "Mr. C. claims, in his vindica- 

 tion, that the whole subject of corals was in his hands, much to my sur- 

 prise, and no doubt to the surprise of all who know that the structure of 

 coral islands is so far a geological question as to constitute an important 

 chapter in all geological treatises. The point was considered so far set- 

 tled at sea as never to have been mooted." 



Here Mr. D. clearly accuses me of having claimed the structure of coral 

 islands, or the geology of corals, as having been placed in my hands. It 

 is untrue that I ever advanced any such absurd proposition. This is what 

 T said, p. 379, Vol. xlv, " It must be borne in mind, that in the distribu- 

 tion of the various departments of natural history among the naturalists 

 attached to the expedition, the corals were especially assigned to me. 

 Their habits, growth, distribution, and all else connected with their his- 

 tory, were consequently the subjects of my particular attention." Is it 

 not self-evident that I here allude only to living corals, to corals zoologi- 

 cally considered, and call attention to the fact of their being assigned to 

 me, as offering a reason why I should naturally have been led to observe 

 the influence of temperature upon their growth 1 At the same time I neg- 

 lected no opportunity of making observations on the geological structure 

 of reefs and islands for Mr. D.'s information, and it was his knowledge of 

 this which led to the proposition by him to publish on this subject jointly 

 with me. I think, however, this was done just prior to our parting in 

 Sydney, and not as he states at Oahu. 



In another foot-note to p. 133, alluding to my statement that I found 

 thirteen fathoms water, with a bottom temperature of 76°, upon a shelf 

 profusely covered with coral, on which we suddenly came in approaching 

 the island of Tutuila, Mr. Dana says, — " By referring to the log-book of 

 the Vincennes, I find that no temperature was taken at any depth on the 

 reef here referred to. The thirteen fathoms were obtained by a cast 

 alongside of the reef; the reef itself on which the coral is growing, varies 

 in depth from 4^- to 7 fathoms. (See expedition charts now publishing.)" 

 The coolness with which all these particulars are applied to a shelf, not a 

 reef of coral, whose locality I have only designated in general terms, is 

 perfectly inimitable. But with all due respect for Mr. Dana's penetration 

 and for the ' expedition charts now publishing,' I take leave to say that 

 their reef with 4^ to 7 fathoms, and 13 fathoms alongside, &c. &-c, is not 

 "the reef here referred to" by me, which was a shelf of coral running out 

 from the shore and gradually deepening, apparently from a few inches to 

 thirteen fathoms. On this I sounded repeatedly, and obtained as nearly as 

 I could estimate from the rude manner of my making the trial, 76° as a 

 bottom temperature. The position and character of this shelf I shall 

 specify hereafter. But, says Mr. D., ' by referring to the log-book of the 

 Vincennes, I find that no temperature was taken at any depth.' By in- 

 geniously substituting a positive statement on this head for a negative one, 



