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HARDWJCKE'S SCIENCE-GOSSIP. 



find three more eggs laid in the old nest. I should 

 be pleased if readers woukl record any similar 

 instance which might have come under their notice. 

 — H. G. Ward, North Mars/oit. 



The Two Sides of the Medal. — Mrs. 

 Bodington, in a not altogether novel parable, urges 

 us to look on both sides of the medal, but gives little 

 evidence of viewing more than one side of it herself. 

 She is apparently more a follower of Spencer than of 

 Darwin, but while she twits Wallace for not being 

 abreast of the march of science, she herself clings to 

 some of the most doubtful of Darwin's assumptions. 

 Of Wallace, she writes : " He believes in natural 

 selection pure and simple, with its odd theory of 

 constant variations occurring without any reason, and 

 owing their origin to nothing in particular." Well, 

 to what do these variations owe their origin in Mrs. 

 Bodington's opinion? They are due to the " law of 

 the action of the environment upon irritable proto- 

 plasms " — an explana'tion highly abstract and more 

 metaphysical than biological. True, probably, as far 

 as it goes, but not going very closely to the point. 

 Now, Wallace, without thinking it worth while to 

 give this account of the origin of variations, has 

 placed the theory of natural selection on a much 

 stronger basis than that on which Darwin built it. 

 Wallace has shown that variations are, as a matter of 

 fact, numerous in all directions. While every 

 organism has a normal or average form and size for 

 all its parts, both internal and external, yet no 

 individual exactly hits this average, but all vary, in 

 all their parts more or less, from the average form 

 and size. For instance, suppose a bird has a wing 

 of a certain length, and it would be to its advantage 

 to have a somewhat longer wing. , Now about half 

 the individuals of the species must always have a 

 little more than the average length of wing, while 

 the other half have a little less than the average. 

 The former will tend to prosper and propagate their 

 kind, while the latter will decrease. The process 

 begins at once. There is no waiting for fortuitous 

 variation, as Darwin thought. Now, as for the 

 transmission of acquired characters, when we find 

 two men so widely apart in their general views as 

 Wallace and Weissman unite in repudiating that 

 doctrine, we must at least believe that a great deal 

 can be said against it,. and that the question cannot 

 be settled so simply as Mrs. Bodington imagines. 

 From the off-hand way in which she settles the 

 matter, it is evident indeed that she does not clearly 

 understand the question at all. She confounds the 

 doctrine of inheritance of acquired characters with 

 heredity in general. She strangely quotes the trans- 

 mission of the peculiarity of supernumerary fingers as 

 the transmission of an acquired character. She also 

 refers to the transmission to offspring of phthisis and 

 insanity ; but the whole question hinges upon 

 whether these disorders were acquired or congenital. 

 As a great authority stated recently, the actual 

 evidence in favour of the transmission of characters 

 really acquired in the individual's lifetime amounts 

 only to a few scattered anecdotes. I will only say in 

 conclusion that Professor Weissman's theory of the 

 continuity of the germ plasma is far from being as 

 baseless in fact as Mrs. Bodington supposes. In 

 numerous cases it is demonstrable that the repro- 

 ductive cells or tlie rudiments of sexual organs are 

 set apart at an early stage, in the development of the 

 embryo. " They thus include some of the original 

 capital of the fertilised parent ovum intact, they 

 continue the protoplasmic tradition unaltered, 

 and when liberated in * turn they naturally enough 

 develop as the parent ovum did." Preconceived 



theories may sometimes blind men to facts ; but a 

 scientist of the calibre of Professor Weissman does 

 not adopt his theories without some foundation in 

 fact. The transmission of acquired characters is Ijy 

 no means essential to Darwinism. The essence of 

 Darwinism is the principle of natural selection, and 

 this must stand as a vera causa, and as one prime 

 factor in the process of evolution, whatever the other 

 factors may ultimately be proved to be. — J. IF. 

 Baylis, 56, Vine Street, Liverpool. 



CoLoaRS OF Eggs. — It is a curious fact that, while 

 we have more or less plausible reasons by which we 

 account for the varied colours of birds, beasts, 

 insects, and flowers, we seem to have no clue what- 

 ever to the reason for the equally beautiful and 

 wonderfully-varied tints of birds' eggs. It is true, 

 certain generalisations have been attempted. The 

 basis of many of these is that the colours bear some 

 relation to the environment, a protective function 

 being assigned to them. M. Gloger, a German 

 naturalist, many years ago followed this fancy to a 

 considerable extent, and it is frequently still pro^ 

 pounded in popular articles in various journals. 

 According to these theorists, eggs are divisible intO' 

 two classes : self-coloured, and spotted. Simple 

 whites, blues, greens, and yellows, are considered to 

 be most conspicuous, and therefore most dangerous, 

 and these are said to be therefore hidden in hollows 

 or covered nests ; the colours of speckled eggs are 

 supposed to blend with the shades of surrounding 

 objects, or with the lining material of the nest. Of 

 course these theories have no foundation in fact, and 

 in every case the exceptions are as numerous as the 

 examples adduced. Any schoolboy who has gone 

 bird-nesting could produce abundant evidence 

 to refute these notions of cabinet theorists. Dr.. 

 Darwin ascribed the colours of eggs to the objects 

 amongst which the mother-bird lives, acting upon 

 the shell through the medium of the eye. Others 

 have surmised that there may be some relation 

 between the colour of the plumage and that of the 

 eggs. Perhaps the plumage of our domestic fowls 

 varies more than that of any other birds, yet they lay 

 simple white or yellowish eggs, singularly unliable to 

 vary. Chemists have recently brought their science 

 to bear on the subject, and their investigations have 

 led, I believe, to the discovery of two new com- 

 pounds in the pigment of the egg of the emu, these 

 were detected by means of the spectroscope. 

 Abnormal varieties of eggs are worth recording ; and 

 I notice, with pleasure, that several of your readers 

 are acting in accord with Mr. Nunn's suggestion, 

 and forwarding to you reports of such variations as 

 they have met with. As in botany, so in this depart- 

 ment, what were once called monstrosities may act 

 as guides to the past history of the species, and some 

 clue may be found which will enable us to unravel 

 what is at present an inscrutable mystery in zoology. 

 In my own experience I have met with some 

 interesting varieties. White forms of normally 

 deeper-tinted or spotted eggs are by no means rare. 

 The robin often lays a pure white egg in a clutch of 

 normal ones, and in two instances I have met with 

 the entire clutch pure white ; the guillemot very 

 frequently lays eggs almost devoid of spots, but 

 absolutely spotless specimens, although they do 

 occur, are rare. Other white varieties I have met 

 are those of the sparrow-hawk, greenfinch, canary, 

 jackdaw, linnet, house-sparrow, and wren. But the 

 most interesting case in this direction was a clutch of 

 eggs of the red grouse, these were all pure white 

 except one, which was slightly clouded with the 

 faintest approach to coloration. Normally-spotted 



