50 



• KNOWLEDGE <> 



[JusE 23, 1882. 



,<>minon plant compound. Tlip animal in such a case 

 nismifaeturos the sul)stance of the plant, and imitates the 

 ohtluistry of the latter organism. 



^uch is an outline of the rooted and fixed " sea squirt" 

 Its'earlier history, however, is still more interesting. It 

 <le"felopes from the egg in exactly the same fashion as the 

 lanoolet The early stages of the sea .squirt run parallel 

 with those of that fish. Finally, at a certain stage, the 

 vo'ung sea squirt makes its appearance as a free swimming 

 uetive hody, somewhat rescmliling a tadpole, and possessing 

 a long tail. !More wonderful still, the resemblance to the 

 lancelet has become of a closer character. A notochonl 

 is developed, as in the lancelet and young of other 

 Vertebrata, and a nervous system appears above the 

 notficliord, as in tlie lowest fish. 8o, also, the charac- 

 teristic throat, with its clefts, is formed. Now, whilst 

 certain sea squirts appear to remain in this tadpole- 

 stage, most of the species liegin sooner or later to retro- 

 gress and to backslide in development The young sea 

 squirt fixes itself to some object by the suckers with which 

 its head extremity is provided. The tail begins to shrivel, 

 whilst the body enlarges and the throat iiureases in size. 

 Then the atnum and tlie leathery skin are formed, and finally 

 the animal becomes the bag-like organism witli which we 

 started. As a sea squirt, pure and simple, the animal loses 

 all, or nearly all, the characters by which it was related to 

 the lancelet ; and but for the knowledge of what it mis, 

 we should therefore hardly know what a sea squirt (or 

 indeed, any other animal) really t.». 



What, now, are the legitimate inferences to be drawn 

 from the facts above detailed, and which, it may be re- 

 marked, are the common details of modern zoological in- 

 struction ? Firstly, that, whilst the lancelet is the lowest 

 Vertebrate, it shows its affinities to other vertebrates clearly 

 enough in the possession of a notochonl and of the other 

 characters already detailed. Secondly, that the sea squirts 

 .ire the only animals which present any likeness to the 

 lancelet, and through it to other vertebrates — man included. 

 Thirdly, that this likeness is so real and so close in all 

 respects that the affinities of the two groups cannot be 

 douVjted. The likeness is seen not only in the posses- 

 sion of a notochord — found in no other Invertebrated 

 animals — but in the curious throat with its gill-slits, 

 and in the nervous axis placed above the noto- 

 chord. Again, the likeness in the earliest stages of 

 development is still more startling ; the egg of the 

 lancelet and that of the sea-squirt develope in precisely 

 similar fashion. Fourthly, if these likenesses be admitted, 

 it logically follows that they must be susceptible of ex- 

 planation. The only feasible and rational account of the 

 resemblances in question, is that which, through the aid of 

 tlie theory of evolution, attributes the likeness to a common 

 origin or de3cent, as it attributes the differences to modi- 

 fication and adaptation to special ways of life. If this 

 explanation be admitted, it follows, fifthly, that the entire 

 vertebrate series, from the lancelet to man, lias been 

 evolved from a rootrstook represented today by the sea 

 squirt's larva. The Tunicata, in this view, are the far-back 

 progenitors of the vertebrate tribes. 



One has heard frequent allusions to the so-called "base 

 origin " of man as attributed by evolution to the sea squirt 

 lar%-a, and this usually from persons unacquainted with the 

 marvellous details of parallel development in sea squirts 

 and in the lancelet But such persons forget that, traced 

 liaok to its ultimate iKjginnings, the human germ itself is a 

 mere speck of protoplasm about the ^^r^h of an inch in 

 diameter, and indistinguishable in any fashion from the 

 egg of lancelet or of sea squirt Moreover, at a certain 

 stage in man's early hLstory, the developing germ resembles 



tolerably closely that of sea squirt and lancelet, as, later 

 on, it has characters common to all quadrupeds, and only 

 as an ultimate phase exhibits the special features of the 

 human type. In a word, the hard facts of develoi>ment 

 exist, whether we like them or no ; and they alone are wise 

 who can reflect, calmly and placidly and philosophically, 

 that these facts in no wise detract from man's place in 

 nature ; but, rightly viewed, only the more ennoble the 

 humanity that, from such humble beginnings, has attained 

 to the highest twig on the tree of life. Mr. Darwin's own 

 words will bear quoting here: — "The most ancient pro- 

 genitors in the kingdom of the Vertebrata at which we 

 are able to obtain an obscure glance, apparently consisted 

 of a group of marine animals, resembling the larvic of exist 

 ing Ascidians. These animals probably gave rise to a group 

 of fishes as lowly organised as the lancelet; and from these 

 the Ganoids, and other fishes, like the Lepidosiren, must have 

 been developed. From such fish, a very small advance 

 would carry us on to the Amphibians." Mr. Darwin's words 

 are again worth quoting, when, in speaking of the origin of 

 man, he remarks that "it is only our natural prejudice, 

 and that arrogance which made our forefathers declare 

 that they were descended from demi-gods, which leads us to 

 demur to this conclusion (that of man's descent from lower 

 forms). But the time will before long come, when it will 

 be thought wonderful that naturalists, who were well ac- 

 quainted with the comparative structure and development 

 of man, and other mammals, should have believed that each 

 was the work of a separate act of creation." And, finally, 

 concerning the often-assumed degradation of vcM-tebrato 

 ancestry, the late distinguished author of the " Origin of 

 Species " has a noble passage wherein he gives the death- 

 blow to all arrogance of heart and mind respecting the 

 origin of the highest forms : — "Thus we have given to man 

 a pedigree of jjrodigious length, but not, it may be said, of 

 noble quality. The world, it has often been remarked, 

 appears ss if it had long been preparing for the advent of 

 man ; and this, in one sense, is strictly true, for he owes his 

 birth to a long line of progenitors. If any single 

 link in this chain had never existed, man would not 

 have been exactly what he now is. Unless wo wilfully 

 close our eyes, we may, with our present knowledge, ap- 

 proximately recognise our parentage ; nor need we feel 

 ashamed of it The most humble organism is something 

 higher than the inorganic dust under our feet ; and no on<: 

 with an unliiassed mind can study any living creature, 

 however humble, without being struck with enthusiasm at 

 its marvellous structure and properties." 



In a concluding paper I shall deal with the evidence for 

 " Found Links," furnished by a study of fossil and extinct 

 maiiiMials and quadrupeds. 



SrECfLATlON in oloctrical companies' sharoa is becoming very 

 ilnnKcrons for the uninitiutod. Our Bpiritcd contemporary, the 

 Eli'clrical Rerip.w, Revorely comments on one of those companies, 

 namely, tho " Self-Generating Electric Light and Power Company, 

 Limited." A ropreeentative of tho journnl called at the office for 

 information, and was shown a Bnnsen coll and a .Swan lamp. These 

 constituted the stock. Ho was informed that Mr. Simon (tho 

 inventor of the company's embryo spcciiility) had not yet com- 

 pleted his lamp. Mr. Simon ir, ncvertheloss, to rocoivo out of a 

 nominal capital of £300,0(X), tho sum of £120,000. This speaks 

 volumes. Amongst tho works modestly contemplated by tho company 

 is " To manufiicturo bricks, quarry stono, manufacture coraont and 

 concrete, and to construct tunnels or subways for carrying wires or 

 conductors of olectricity, and to construct railways, tramways, or 

 waterways." It is also contemplated to carry on, or at any time to 

 ceaso to carry on (!!!) tho business of mannfactnrors of oloctrical 

 generators or accumulators, lamps of all kinds, Ac. It is to bo 

 feared that we shall hoar a deal of anch companies before tho year 

 is out. 



