184 Transactions. — Zoology. 



Lord Kelvin, the late President of the Royal Society, after 

 thanking me for the address, says : " You and the geologists 

 must, however, be satisfied with twenty million years for the 

 earth's age. The 306 million years for the denudation of the 

 Weald in Kent, given as part of his foundation in the first 

 edition of 'The Origin of Species,' was dropped by Darwin 

 himself after I showed it to be inconsistent with dynamics, 

 and I think you will not find it in the third or later editions. 

 The 270 million years ' since the Cambrian period,' which you 

 quote from Lyell, is utterly untenable. He supported his 

 assumption of infinite past time for geology by a thermo-electric 

 invention of a perpetual motion as good as many of the million 

 ' perpetual motions ' that have been invented by ingenious 

 persons who have not learned dynamics or physics." 



A sufficient length of time was my postulate ; and twenty 

 million years suits my argument quite as well as the more- 

 extended period. 



Sir John Lubbock, F.R.S., whom I gently twitted with 

 inaccuracies, whilst I admitted to the fullest extent the charm 

 of his writings, writes to me : " Many thanks for the ' Illustra- 

 tions,' which I have read with much interest. Huia is, of 

 course, allied to the Crow, and I said Crow rather than Star- 

 ling as giving a better idea of the size and colour. I observe 

 you say that the female ' comes to the aid ' of the cock, 

 so that my account does not differ so very much from what 

 you say. Probably if the cock has not had enough he would 

 take some. " 



Professor Parker, F.E.S., writes: "I have read your 

 article, 'Illustrations of Darwinism,' with some care, and 

 approve highly of most of it. There are a few criticisms I 

 should like to make. 



" P. 79. The upper mandible (oiAjyteryx) is a prolongation 

 of precisely the same bone as in other birds — premaxillae, 

 nasals, &c. The ' cranial pan ' is rather exceptionally large 

 in AiJtcryx. I have often wondered what it wants witia such 

 a big brain. 



" P. 80. You are quite right about the extreme specialisa- 

 tion of A2)teryx. See my paper on its development : ' Philo- 

 sophical Transactions, 1891,' summary, p. 116. See also the 

 brief account of the matter in the ' New Zealand Journal 

 of Science ' (sent herewith). 



"P. 85. Mcgalapteryx is not a 'Giant Kiwi,' but a Moa, 

 as Lydekker first showed. 



" P. 87. My observations on the skull of the Dinornithidge 

 (see Proc. Zool. Soc, 14th Feb., 1893) distinctly contradict 

 your view that the larger forms of Moa are the most ancient. 

 The oldest (least specialised, &c.) type of skull is Mesoj^teryx 

 (including Casuarinus, DicUnus, &c.), while the very tall forms 



