174 



NATURE 



{Dec. 26, 1889 



enough that variations must be governed by some law. But as 

 we are absolutely ignorant what that law is, he thought it 

 allowable to make provisional use of the word accidental. But 

 the "neo- Darwinians" (as Prof. Ray Lankester calls them) are 

 not content with this dethronement of their idol, Fortuity. The 

 supreme and everlasting rule of pure accident is their creed and 

 worship. Hence comes Prof. Ray Lankester's simile of the 

 kaleidoscope, by which he illustrates the genesis of "new cha- 

 racters " in organic life. There is, he indicates, no more con- 

 nection between those "new characters " and their origin in the 

 parent, than there is between the new patterns which tumble in 

 a kaleidoscope and the tap upon the tube which shakes them out. 

 There is no argument so false as a false analogy. And this 

 is a case in point. Every illustration or analogy must be false 

 which confounds mere mechanical arrangement with organic 

 structure. They are not only different, but they are different in 

 kind. Neither mechanical aggregation, nor mechanical segre- 

 gation, can possibly account for the building up of organic 

 tissues. To attempt to account for such structures by causes 

 similar to those which determine the arrangement of tumbling 

 bits of glass, is even more irrational than it would be to account 

 for the structure of a great cathedral by explaining to us how 

 its bricks or its stones were made. There is one grand pecu- 

 liarity in all organic structures which all such illustrations are 

 framed to conceal. That grand peculiarity is this — that they 

 are all made for work, for the discharge of some function. They 

 are where they are not merely because somehow they have 

 been put there. But they are what they are, and where they are, 

 because they have some given work to do. But more than this : 

 they all pass through stages of development in which their work 

 cannot as yet be done. In all these stages, that work lies before 

 them in respect to time, and behind them in respect to adapta- 

 tion. They are all of the nature of an " apparatus." This is 

 the word which the profound but unconscious metaphysic of 

 human speech has invented for them. It is the word chosen by 

 natural selection, and, as such, it ought to secure the homage 

 even of Prof. Ray Lankester himself The idea, however, comes 

 before the word — shapes it, and inspires it — ^just as the needs of 

 function, and the organic necessities imposed by inorganic laws, 

 have shaped and inspired the growth and development of every 

 organic apparatus. 



I am very glad to see that under the stress of controversy the 

 Professor admits — and even hotly denies that it has ever been 

 doubted — that natural selection cannot account for the pre- 

 existence of the structures which are presented for its choice. 

 And not only must selected organs exist before they can be 

 chosen by natural selection, but they must have been already 

 sufficiently developed to possess some functional activity. This 

 was my contention thirty years ago, and to this day I have 

 always found it either denied or evaded by the whole ultra- 

 Darwinian school. I rejoice to see it now admitted as unques- 

 tionable. "Natural selection can account for the origin of 

 nothing" — so says Mr. Cope. The Professor indignantly re- 

 plies : " How can Mr. Cope presume to tell us this? Who has 

 ignored it ? when ? and where ? " So ends a long and a hard 

 fight. The enemy not only lays down his arms, but denies he 

 has ever carried them. Argyll. 



Who Discovered the Teeth in Ornithorhynchus ? 



It is almost superfluous to add anything to Prof. Flower's 

 reply (p. 151) to Dr. Hart Merriam. Injustice, however, to 

 Mr. Poulton, it ought, I think, to be stated that he fully refers 

 to Home's paper in the Philosophical Transactions. In the 

 Quart. Jotirn. Micr. Set., vol. xxix. p. 27 (a paper to which Dr. 

 Hart Merriam alludes as though he had read it) Mr. Poulton, 

 describing the horny plates of Ornithorhynchus, writes as follows : 

 "Home (Phil. Trans., 1802, p. 71) correctly describes these 

 horny plates as differing ' from common teeth very materially, 

 having neither enamel nor bone, but being composed of a horny 

 substance only embedded in the gum,'"&c. I observe too, 

 with great interest, that in the same paper Home makes use of 

 the expression (p. 70) "the teeth, if they can be so called." On 

 p. 28 Mr. Poulton quotes in full the passage from Owen given 

 by Prof. Flower. Perhaps Dr. Hart Merriam does not accept 

 Owen's correction of Home's hypothesis. It is hardly necessary 

 to point out that the teeth which Mr. Poulton describes (p. x$ et 

 seq.)\ixi^QX the headings (i) tooth papilla; (2) dentine; (3) 

 enamel ; (4) inner epithelium of enamel organ ; (5) stratum inter- 

 medium of Hannover ; (6) middle membrane of enamel organ ; 



and (7) outer membrane of enamel organ, must be very different 

 from those which Home calls "cuticular," and further qualifies 

 as in the sentence which I have quoted. 



Comparison of Home's figures with Mr. Oldfield Thomas's 

 (Proc. Roy. Soc, vol. xlvi. pi. 2) renders it highly probable that 

 the true teeth of Home's younger specimen had only recently 

 dropped out from the horny plates ; the dimensions given by the 

 two authors being almost identical. But Home's description is 

 perfectly definite, and no hint whatever is made to true teeth 

 situated upon the horny plates such as those described and 

 figured by Mr. Oldfield Thomas. The length of the skull of 

 Home's specimen, as given in his figure, is 71 miUimetres, while 

 that of Thomas's female specimen is 65 millimetres ; the male is 

 slightly larger. Probably, therefore. Home's specimen was 

 considerably older than Thomas's, and had lost the true teeth 

 for some little time. 



The only conclusion at which I can arrive is that Dr. Hart 

 Merriam did not read any of the three papers bearing on this 

 subject with sufficient care and attention to enable him to fully 

 understand the facts ascertained by their respective authors, if 

 indeed he proceeded further than the introductory remarks pre- 

 facing Mr. Oldfield Thomas's communication to the Royal 

 Society. Oswald H. Latter. 



Anatomical Department, Museum, Oxford, December 20. 



Galls. 



In answer to Mr. Ainslie HoUis, I should like to observe 

 that, in my opinion, the theory of natural selection is not 

 " seriously assailed by investigations into the formation of galls 

 by insects." On the contrary, in reply to what appeared to be 

 a challenge from Mr. Mivart, I pointed out the manner in which 

 natural selection might here be fairly supposed to have operated. 

 But, while doing this, it appeared desirable to add that the case is 

 a highly peculiar one. If galls were merely amorphous tumours, 

 or even if they presented but as small an amount of specializa- 

 tion for the benefit of the larvae as is presented by animal tissues 

 for the benefit of their parasites, the case would not be so 

 peculiar. But the degree of morphological specialization which 

 the "pathological process" presents in the case of some galls — 

 and this, of course, for the exclusive benefit of the contained 

 parasites — is very remarkable. And although I doubt not that 

 it is but a higher exhibition of the same principles as obtain in 

 the case of animal tissues and their parasites, it is a case of 

 much greater interest from the Darwinian point of view. For, 

 if the explanation given in my last letter be accepted, the facts 

 show how enormous must be the power of natural selection 

 in building up adaptive structures, seeing that it can do this in 

 so high a degree even when working, as it were, at the end of a 

 long lever of the wrong kind — i.e. acting indirectly on the veget- 

 able tissues through the benefits thereby conferred on their ani- 

 mal parasites. I am not aware that there is any other instance 

 of "symbiosis" where so high a degree of adaptive specializa- 

 tion is presented by one of the " partners " for the exclusive 

 benefit of the other. George J. Romanes., 



London, December 13. 



Mr. W. Ainslie Hollis has involuntarily misrepresented 

 me as saying that the theory of natural selection can be 

 "seriously assailed" by investigations respecting galls. I 

 said, indeed (Nature, November 14, p. 41), that it would be 

 "very interesting to learn how" natural selection could have 

 caused them ; but I was careful to add that doubtless an ex- 

 planatory hypothesis was ready to hand. I do not myself 

 believe they were so caused ; but if they were not, they would 

 none the less, like almost all biological phenomena, be explicable 

 by an unlimited use of gratuitous hypotheses concerning physio- 

 logical correlations and imaginary ancestors. 



I confess I do not see that calling them "pathological" (an 

 epithet I certainly would not deny them), and comparing them 

 with inflammatory renal foci due to Bacilli, will explain them, 

 unless it be affirmed that pathological conditions favourable to 

 parasites are always due to the action of " natural selection" on 

 the parasites themselves — an affirmation which appears to ask 

 too much. 



Herr Wetterhan's argument from symbiosis sins against natural 

 selection itself. For that theory requires that, in the arduous 

 and incessant struggle for life it supposes, any prejudicial 

 growth should, in time, be eliminated unless carrying with it 

 some preponderating advantage. The insect and the plant are 



