Oct. 19, 1876] 



NATURE 



543 



We shall therefore conclude with a remark on Dr. 

 Maudsley's attempt to make something of the will — that 

 apparent point of contact of the physical and the mental, 

 which has been the veritable will-o'-the-wisp of our 

 psychologists. Towards the end of his book (p. 442) Dr. 

 Maudsley, in examining a " simplest case of volition/' 

 tells us that it " sprang from that fundamental property 

 of organic element by which what is agreeable is sought, 

 what is painful is shunned." This is not advancing 

 knowledge, but rather the reverse. How can any sub- 

 stance, whether we call it organic element or by any 

 other name, seek the agreeable and shun the painful ? 

 By movements ; we know of no other way of seeking 

 and shunning. But how are these mental things, pain 

 and pleasure, related to movements of any kind 1 Here 

 we find ourselves, after much laborious groping, face to 

 face with the very problem we set out to solve. Truly 

 what we have to learn in psychology, before and above 

 all things, is our ignorance. 



Douglas A. Spalding 



OUR BOOK SHELF 



Animal Record of Science and Industry for 1 875. Edited 

 by Spencer F. Baird, with the assistance of eminent 

 men of science. (London : Triibner and Co., 1876.) 

 For this admirable record we have again to thank our 

 American friends. The volume now extends to some 

 900 pages, and each year brings improvement as well as 

 enlargement of its contents. Unfortunately so many 

 subjects are now embraced within the scope of this 

 annual record, that the space devoted to each subject is 

 necessarily curtailed. This, we think, is a misfortune. 

 If feasible, we would venture to suggest a division of the 

 record into two parts, inasmuch as pure, applied and 

 very homely science are here in close and curious juxta- 

 position. Thus we find " tables of elliptic integrals," the 

 "computation of the areas of irregular figures," or the 

 " dissipation of energy," followed by " beautiful ornament 

 for rooms," " renewing wrinkled silk," and " improved 

 modes of closing barrel hoops." It is true the editor has 

 most carefully and laboriously classified the v.'hole, so 

 that we are gradually let down from elliptic integrals at 

 the beginning to barrel hoops at the end. Doubtless the 

 editor considered that by these things men would learn 

 " beer and skittles " was an integral part of the scientific 

 as well as the popular need. The first half of the work, 

 which gives a general summary of scientific and industrial 

 progress for the past year, is more carefully edited than 

 the larief notices of papers which form the second half. 

 For example, turning to general physics, we find para- 

 graphs on Mr. Crookes' experiments scattered about 

 m several places ; the same is true of Dr. Guthrie's 

 researches on cryohydrates and of several others we 

 might name. Again, in the index, which is extremely 

 minute, the same name is put under different headings ; 

 thus, Mr., Mr. Frederick, and Prof. Guthrie are the same 

 person, though separately referred to. But in spite of 

 these criticisms, the book is a useful one and contains a 

 vast mass of information. Sketchy as it is, nevertheless 

 it is undoubtedly the best annual record of science — in 

 fact the only one in the English language ; and hence we 

 are glad to observe that a suggestion we made in noticing 

 the preceding volume, namely, having a London as well 

 as a New York publisher, has now been carried out. The 

 scientific bibliography of the year and the references to 

 periodicals, giving the fullest reviews of the books them- 

 selves, is an excellent and valuable feature of this Record. 



Causer ies Scientifiques. J. Rothschild, Editeur. (Paris.) 

 This little book gives a brief and popular account of 

 some of the principal discoveries and inventions of the 



past year. It is written in a lively, simple style, and 

 doubtless has done something in France to extend an 

 interest in science and to spread a knowledge, though 

 but a superficial one, of the more striking results of expe- 

 rimental research. The absence of technical terms 

 brings the volume before us within the comprehension of 

 those who have had no scientific education. How is it 

 we are so behind our neighbours in books of this kind? 

 It would, however, have been well if the editor of this 

 volume had paid a little more attention to the spelling of 

 English names, and exercised closer supervision through- 

 out, as we notice several misprints in its pages. 



LETTERS TO THE EDITOR 



[77ie Editor does not hold himself responsible for opinions expressed 

 by his correspondents. Neither can he undertake to return, 

 or to correspond with the writers of, rejected manuscripts. 

 No notice is taken of anonymous communications. ^ 



The Self-fertilisation of Plants 



Some years ago my suspicions were strongly aroused by certain 

 observations, against the importance of intercrossing ; and since 

 then other conclusions, such as the following, have been steadily 

 forcing themselves upon me, and which will probably agree with 

 Mr. T. Meehan's : (i) that self-fertilisation was the primordial 

 condition of plants ; (2) that conspicuous flowers of all kinds are 

 a secondary result, due to insect agency, by increasing the size 

 &c., of the perianth; (3) that this has, in its turn, caused a 

 correlative disturbance in the sexual arrangements, viz., that it 

 has caused to be sacrificed the (originally) normal state of self- 

 fertilisation, and has set up cross-fertilisation instead ; (4) that 

 this latter being relatively less certain of being effected, is com- 

 pensated for by a superabundance of pollen, alteration in its 

 form and influence, dimorphism, the separation of sexes, and 

 perhaps other details of sexual differentiation ; (5) that the exist- 

 ing self-fertilising flowers are in no case primordial but degraded 

 forms ; (6) that in consequence of such degradation, of the 

 perianth especially, the sexual organs have recovered their 

 original energies, and so resume their long lost self-fertilising 

 powers. 



The rationale cf the whole process I take to be " compensa- 

 tion." In the first instance, the enlargement of the corolla is 

 accompanied either by a more or less degree of destruction of 

 one or both of the sexual organs ; as in the ray-florets of Cen- 

 taurca, which are neuter; in "double" flowered compositse, 

 where the new "ligulate" ones pass from the usually her- 

 maphrodite condition of the tubular disk florets, or male, as 

 in Calendula, to female only, or even to the neuter state, as in 

 Dahlia ; or else by the above-mentioned differentiations of 

 the sexual organs in their forms and functions. The primary 

 cause of such increase in the perianth may, perhaps, be due to the 

 mere mechanical influence of the insects themselves, which by 

 constantly renewed pressure, may determine a flow of nutriment 

 to those parts ; this — which I only assume as probable — diverts 

 it temporarily from one or both whorls of essential organs. The 

 result is protandry or protogyny, &c. To compensate again 

 for the loss of self-fertilisation, there come into play, as stated 

 above, all the adaptations to secure inter-crossing. Hence the 

 idea of plants abhorring inter-breeding appears to have arisen 

 from observing conspicuous flowers only, and as these are in the 

 majority nowadays, it was a reasonable conclusion : but the self- 

 fertilising ones are extremely numerous altogether ; and it is this 

 small but highly significant minority, not to add the special 

 contrivances which occur in order to secure self-fertilisation, 

 which leads one to the opposite conclusion. 



Self-fertilisation I believe not to be always an absolute but a 

 purely relative condition ; that although many species are now 

 altogether self-fertilising, yet whenever conspicuous flowers be- 

 come dwarfed, I suspect there is a tendency to their becoming self- 

 fertilising. I have found it to be so in some cases, and should feel 

 extremely glad if any readers of Nature would kindly observe, 

 at this season of the year especially, whether any dwarfed wild 

 or other flowers they can find are self-fertilising or not, or^lse be 

 good enough to forward the same to me. For example, I have, 

 this September, found dwarfed blossoms of Linaria vulgaris 

 often spurless and without honey, having the stigma situated 

 between the two pairs of anthers, and the pollen-tubes pouring 

 into it both from above and below. Similarly in small flowered 



