November 29, 1889.] 



SCIENCE. 



375 



lying upon the shore a cut of a large fir-tree, of about 2-| foot 

 diameter and 9 or 10 foot long, which had lain so long out of the 

 xwater that it was very dry; and most of the shells that had for- 

 merly covered it were worn or rubbed off. Only on the parts that 

 lay next the ground there still hung multitudes of little shells, hav- 

 ing within them little birds perfectly shaped. . . . The shells hang 

 on the tree by a neck longer than the shell ; of a kind of filmy sub- 

 stance, round and hollow, and creased,. not unlike the windpipe of 

 a chicken, spreading out broadest where it is fastened to the tree, 

 from which it seems to draw and convey the matter which serves 

 for the growth and vegetation of the shell, and the little bird within 

 it. . . . This bird in every shell that I opened, as well the least as 

 the biggest, I found so curiously and completely formed that there 

 appeared nothing wanting as to the internal parts for making up a 

 perfect sea-fowl ; every little part appearing so distinctly that the 

 whole looked like a large bird seen through a concave or diminish- 

 ing glass, color and feature being everywhere so clear and neat. 

 The little bill like that of a goose, the eyes marked, the head, 

 neck, breast, wings, tail, and feet formed, the feathers everywhere 

 perfectly shaped and blackish colored, and the feet like those of 

 other water-fowl to my best remembrance." 



Such was the old belief existing during five centuries, at any 

 rate, and probably accepted at periods both earlier and later than 

 those from which the preceding examples are taken. To modern 

 observers it seems utterly absurd. Science has shown its absolute 

 groundlessness as natural history ; and Professor Max Miiller, to 

 complete the rout, has put forward, in his " Lectures on the Sci- 

 ence of Language," a very interesting theory of its probable origin 

 from the point of view of philology. But the*latest researches have 

 shown that the barnacle has been' deposed from his place in a 

 mythical metamorphosis, only to take part in his life-history as now 

 ascertained in another transformation scene quite as wonderful, 

 and this time vouched by the careful observations of our best 

 naturalists. 



In the adult state, Mr. Seville goes on to say, the barnacle con- 

 sists of a shell-fish permanently attached, by a fleshy peduncle or 

 stalk, to a piece of timber or rock of some other object in the sea. 

 The shell opens by a peculiar valve-like arrangement, and, through 

 the aperture thus formed, several pairs of long, many-jointed 

 " cirri," or feelers, are put forth, which, by their constant waving 

 motion, whirl to the creature's mouth the small particles which 

 form its food. Huxley's description is concise and expressive : 

 "A crustacean fixed by its head, and kicking the food into its 

 mouth with its legs." It is not the change of this creature into a 

 goose that science can now surprise us with : that story must be 

 given up along with the accounts of griffins, phoenixes, and drag- 

 ons. The fruit theory as to its origin must also be abandoned ; 

 but, though the new account does not involve quite so violent a 

 transition as that from the vegetable to the animal kingdom, it is 

 still in the steps by which the adult form is reached that those 

 changes are revealed which almost entitle the barnacle to the rep- 

 utation for facile metamorphosis with which our forefathers credited 

 it. The steps in question are (besides the egg) the two stages 

 known respectively as the Naiipliiis and Cypris stages. Immedi- 

 ately on its escape from the egg, the young barnacle appears as an 

 animal of microscopic size, acljve and free-swimming, equipped 

 with a broad shell or shield on its back, and having three pairs of 

 legs, a single eye, a mouth, and a forked tail. This is \\\& Naii- 

 plucs, and in outward appearance the young creature exhibits at 

 this stage no single point of resemblance to the parent form. It 

 feeds and grows apace, and moults several times. It then enters 

 the next condition of its existence, — the Cypris stage. The broad 

 shield-shaped carapace becomes folded together, somewhat after 

 the pattern of a bivalved shell, and almost encloses its owner. The 

 foremost limbs are transformed into a very peculiar pair of suc- 

 torial or adherent feelers, and the two hinder pairs are cast off, 

 their place being taken by six pairs of powerful swimming-legs 

 with bifid extremities. A pair of compound eyes is another new 

 feature of this stage ; and altogether the Cypris, while still quite 

 distinct from the adult barnacle, presents a very different appear- 

 ance from the Naupliiis. The mouth is wanting, or at least is 

 functionless, being covered by an integument without aperture. 

 Existence in this stage is therefore necessarily short, and the 



Cypris soon fixes upon its future abode by attaching itself by its. 

 suctorial feelers to some piece of drift-wood, pile, or rock. A kind 

 of cement, which it secretes by means of special glands, pours out 

 round the base of attachment, and quickly hardens, gluing the ends 

 of the feelers firmly to the surface on which they rest. The com- 

 pound eyes are shortly afterwards moulted, the body straightens 

 out, and the shell thus comes to stand almost perpendicularly to 

 the surface of attachment. Other changes follow : the shape of 

 the shell is modified, and the position of the animal within alters in 

 such a manner that the under surface of its body is turned directly 

 away from the point of attachment; the integument covering the 

 mouth is cast off ; the legs cease all swimming ambulatory functions,, 

 and soon become mere cirri, sweeping the water for prey ; the feelers, 

 are gradully covered with a fleshy pulp, and, losing all trace of 

 their old form, are converted into a single stalk of attachment ; the 

 new parts of the shell which are to form the valvular opening, and 

 other protecting plates, begin to form, and, for all practical pur- 

 poses, the barnacle, though still very minute, has attained its adult 

 form, future development being mainly in the matter of size. 



The old legend involved a double change from fruit to fish, and 

 from fish to bird ; the new history also deals with a double change,, 

 from Naupliiis to Cypris, and from Cypris to barnacle. For one 

 series of wonders another has been substituted, and, if this is not 

 sufficient to restrain us from too hastily condemning our fore- 

 fathers' credulity, it will be well to remember how recently we have 

 arrived at the truth. Little more than fifty years ago the position 

 of the barnacle in the animal kingdom was still completely un- 

 settled. Agreeing in most of its outward characteristics with the 

 Mollusca, it was commonly classed with them. The Naupliui 

 and Cypris were not connected with the parent form, but, if de- 

 scribed at all, were treated as distinct animals. In 1830 J. Vaughan 

 Thompson's description of his observations of their metamor- 

 phoses cast a new light on the subject; but the question still re- 

 mained somewhat open ground for naturalists, and it was not until 

 1851-53 that Darwin, in his " Monograph of the Cirripedia," defi- 

 nitely settled the barnacle's claim to be classed with the Crus- 

 tacea, and established beyond dispute the facts of its complicated 

 and peculiar life-history. 



BOOK-REVIEWS. 



The Development of the Philosophy of the Stea7n-Eiigijie. By 

 Robert H. Thurston. New York, Wiley. 16°. 75 cents. 



This historical sketch, which relates not only to the steam- 

 engine, but also to the various heat-engines embodying the same 

 principles, was originally prepared by Professor Thurston some five 

 or six years ago, and was presented in the form of a paper to the 

 British Association for the Advancement of Science in 1884, at its 

 Montreal meeting. The paper was favorably received, and was 

 incorporated in full in the association's " Transactions " of that 

 year. Believing the time appropriate for the publication of such a 

 sketch, he now gives it to the public in a more permanent and ac- 

 cessible form. Though the author does not hold that the theory 

 of the steam-engine is yet in its final perfect and complete form, he 

 believes that the main principles and essential facts of a complete 

 theory are well determined and well recognized by advanced 

 thinkers and intelligent practitioners. This view of the case, we 

 think, will not be disputed ; and all persons concerned in engine- 

 designing will find this sketch of the development of the philosophy 

 of the steam-engine a valuable guide in working out future im- 

 provements. 



Oceania : Linguistic a?id Anthropological. By Rev. D. MaC- 

 DONALD. Melbourne, M. L. Hutchinson ; London, Sampson 

 Low. 16°. 



The author takes the stand that the ancient Oceanic mother- 

 tongue was a branch of the Semitic family, and that while, like the 

 other languages of this stock, it had much in common with all the 

 rest of phonetics, grammar, and vocabulary, it had certain peculiar- 

 ities, and that therefore the modern OiTeanic dialects are Neo- 

 Semitic, " somewhat as Modern Syriac." The author compares 

 Malagassy, Malay, Efatese, and Samoan with many Semitic dia- 

 lects, and calls his new family Semitic-Oceanic. The author can 

 hardly claim to have succeeded in proving such a relationship. 



