On the Structural Relations of Organized Beings. 525 



this letter previously published (p. 116) requires to be thus 

 corrected. " Priestley addressed this paper to the Royal So- 

 ciety on the 21st of April 1783 : and therefore the communica- 

 tion of Cavendish's experiments, acknowledged in it as having 

 suggested his own, must have been prior to the speculations 

 founded thereon which Watt addressed to Priestley on the 

 26th of the same month, as well as to Lavoisier's experiments 

 which followed in June." 



LXXIX. Observations on Mr. Strickland's Article on the 

 Structural Relations of Organized Beings. By Prof. Owen, 

 F.R.S. 



To the Editors of the Philosophical Magazine and Journal. 

 Gentlemen, 

 r T*HE author of the interesting paper " On the Structural 

 Relations of Organized Beings," in your last Number, 

 appears, — in recommending the introduction of " the adjec- 

 tive affine or homologous in place of analogous, when referring 

 to structures which essentially correspond in different organic 

 beings " (p. 358), — not to have been aware that the term 

 ' homologous ' had been used in the sense he recommends, 

 by comparative anatomists both in this country and abroad 

 for some years past. 



In the article Marsupialia, for example, Cyclopaedia of 

 Anatomy, part 21, April 184-1, p. 283, he will find—" With 

 reference to the interesting question, — What is the homology 

 or essential nature of the ossa marsupialia ? " — and their homo- 

 logies discussed. In No. XXII. of the same Cyclopaedia, 

 article Monotremata, p. 375 : " The interposed cartilages, 

 which thus form a third element in the costal arch, repeat a 

 structure common in Crocodiles, and may be regarded as the 

 homologues of the costal appendages in the ribs of birds." And 



notice of his having quoted a private letter to the son of Mr. Watt on the 

 subject of his father's claims. I am aware that Lord Brougham says he 

 has seen such a letter, and says also that the opinion expressed in it re- 

 specting Watt's MSS. is different from the opinion attributed to Dr. Henry 

 by me : but I am not aware that Lord Brougham has given any quotation 

 from this letter ; nor if he had, would any partial quotation have satisfied 

 me, that Dr. Henry's opinion was at any time different from that which he 

 expressed to me, when I mentioned to him the sentiments which I had 

 heard fall from M. Arago concerning the MSS. at Aston, and the insin- 

 cerity of Cavendish. Dr. Henry then said, that he had seen nothing in 

 those MSS. either to justify that impression, or to alter the received 

 opinion respecting the discovery of the composition of water. Who 

 indeed can doubt but that the MSS., had they contained any evidence to 

 support an object which has been so long urged by private solicitation, 

 would have been made public long ago? 



