Part 2 (1/2)

It ith a view of the anian his work on the Medusae of the tropic seas He began to study the the most abundant of the animals that could be obtained fros, and, above all, studied theirCuvier's _Radiata_, but, as Huxley said in the first line of his meated with so little satisfactory and comprehensive result, and this not for the want of patience and ability on the part of the observers, but rather because they have contented theenera and species, instead of giving broad and general views of the whole class, considered as organised upon a given type, and inquiring into its relations with other families”

He found that fully developed Medusae consisted each of a disc with tentacles and vesicular bodies at the enerative organs He traced this sih the complications and roups of Medusae, in all this work bringing out the prevailing features of the anatomy in contrast to the individual peculiarities He shewed that microscopically all the coans were composed of two ”foundation-membranes,” two thin webs of cells, one of which formed the outer of the stomach and canals in the thinner parts of the body, such as the edges of the umbrella-like disc, and towards the ends of the tentacles These thin webs formed practically all the body In the thicker parts there was interposed between the between the lining and the cloth of a coat He shewed that blood-vessels and blood were absent, in which he has been confirainst the existence of a special nervous syste after, when the ation were much more perfect, that the delicate nerve-cells and nerve-fibres, whichto exist, were discovered

Having thus shewn the peculiar organisation of the group he turned to seek out its allies a other families The Medusae consisted essentially of twoa variously shaped cavity inasans were external, being variously developed processes of the two ans called thread-cells--poisoned darts by the discharge of which prey could be paralysed--were universally present What other families presented these peculiarities?

There are to be found abundantly in sea-water, and less frequently in fresh water, innumerable forms of animal life called Zoophytes or ani masses like lichens, or branched forests like ave this set of creatures their coether, there was no greater affinity a people who clothe the party in the sae nureat families of polyps, the Hydroid and Sertularian polyps, which each consist of colonies of creatures very much like the little fresh-water hydra He shewed that the tubular body of these and the ring of tentacles surrounding the mouth were composed of the saans of Medusae are composed

He found in them the poisoned arrows or thread-cells of the Medusae, and the saans And, lastly, he separated froroup, soest and most beautiful animals of the tropic seas, known to science as the Physophoridae and the Diphyidae

The best-known of these is the ”Portuguese e pear-shaped vesicle which floats on the water like a bladder Froe and s in atentacles aring protrusions bear the grape-like reproductive organs On the upper surface of the bladder is fixed a purple sail of thecreature is blown through the water When the weather is rough, the bladder empties, and the creature sinks down into the quiet water below the waves, to rise again when the storm is over This, and its equally wonderful allies, Huxley showed to be a co composed of two membranes, and therefore essentially sireat piece of constructive work, an asseroup and shewn to be organised upon one simple and uniform plan, and, even in the most coroup, and Huxley's conception of its structure, are now absolutely accepted by anatomists, and have ees, concerning the exact relations of which there is still dispute, and of a few sets of parasitic and possibly degenerate creatures, all animals, the bodies of which are multicellular, from the siroups The structure of the siroups is exactly what Huxley found to be of importance in the Medusae The body wall, froans protrude, consists ed in two sheets or le cavity consists of a central sto si canals The doether, with the addition of the sea-anemones and the medusa-like Ctenophora, which, indeed, herelated to the others, but reserved fuller consideration for a future occasion This group is now called the Clenterata, the na that the creatures are siest ith the group Cloher animals, from the simplest worm up to man; animals in which, in addition to the two foundation-membranes of the Clenterata, there is a third foundation-membrane, and in which, in addition to the simple stomach cavity with its offshoots, there is a true body-cavity or clo a blood-fluid The older roups of aniered on for some years in text-books and treatises, but in this eon had replaced it by the ether only because of real identity of structure

There is yet left to be noticed perhaps the most wonderful of all the ideas in this firstthe two foundation membranes of the Medusae he rehout, the outer and inner ical relation to one another as do the serous anddeveloped into the ans of offence and defence: the inner on the other hand appearing to be eneration”

In the whole range of science it would be difficult to select an utterance e than these feords

Huxley had been reading the investigations of Von Baer into the early developreat generalisation, that the younger stages of these anies, and that in an early stage in the develop of the embryo consists of two layers of cells, in fact of two foundation-estive canal, the other for the most external portion of the future ani could have seemed a remoter or more unlikely comparison than one instituted between Medusae and the ees of back-boned aniht before his reason to be swamped by preconceived ideas At the time he did no more than to make the comparison It was much later that the full importance of it becay of vertebrates and of the different groups of the invertebrates had made it plain that the two foundation-membranes of Huxley occur in all aniroup of Clenterata the organisation re in and folding out of these her animals similarly consist of complications of the two membranes; but later on there is added to theether comprises those animals that as adults reh in the eher animals The immense importance of this conclusion becomes plain, and the conclusion itself seeht of the doctrine of descent The group of Clenterata represents a surviving, older condition in the evolution of aniarded evolution only as a vague metaphysical dream, and he made the coht of what it implied In this we have the earliest authentic instance of the peculiar integrity of s with philosophy and tradition He never allowed any weight of authority or any apparent disturbance of existing ideas to alter the conclusions to which his reason led hie made hiainst traditional thought, and we shall find again and again in consideration of his work that it was the keynote of his life

CHAPTER IV

EARLY DAYS IN LONDON

Scientific Work as Unattached shi+p-Surgeon--Introduction to London Scientific Society--Translating, Reviewing, and Lecturing--Ascidians--Molluscs and the Archetype--Criticisical Survey

The _Rattlesnake_ was paid off at Chatham on November 9, 1850 In the natural course of events Huxley would have been appointed before long to active service upon another shi+p But he had no intention of relapsing into the position of a mere navy doctor; he had accumulated sufficient scientific ation for years, and so he applied to the Adard_ at Woolwich,--that is to say, to be appointed assistant-surgeon to the shi+p ”for particular service,” so that he should not be coht remain in town, and, with free access to libraries and museums, work up the observations he had made on the _Rattlesnake_ into serious and substantial contributions to science His request was granted, largely by the aid of his old chief, Sir W Burnett, who continued to take the inally nominated to the service In a letter to hiations which he desired to continue as being chiefly those on ”the anatomy of certain Gasteropod and Pteropod Mollusca, of Firola and Atlantis, of Salpa and Pyrosoma, of t Ascidians, naitta and certain Annelids, of the auditory and circulatory organs of certain transparent Crustacea, and of the Medusae and Polyps” His request was granted, and for the next three years Huxley lived in London with his brother, on the exiguous incoeon, and devoted himself to research He becalish anatomists The result of the paper on Medusae in the _Transactions of the Royal Society_ was that he was elected a Fellow of the Society on June 5, 1851, and a year later received a Royal Medal of the Society Hethe older and the younger generations of scientific men In his obituary notice of Huxley, Sir Michael Foster wrote:

”By Edward Forbes, in whose nature there was much that was akin to his own, and horeeted as a comrade, and with Joseph Dalton Hooker, to whom he was drawn at the very first by their coan an attachrew closer as their lives went on In the first year after his return, in the autumn of 1851, heof the British association at Ipswich, and the three, Hooker, Huxley, and Tyndall, finding how much in common were all their scientific views and desires, formed then and there a triple scientific alliance”

Repeated efforts were made by these three, and by more influential friends, to induce the Ad Huxley's scientific results, as they had given a pledge to encourage officers who had done scientific work These efforts lasted unavailingly for nearly three years, and then, as Huxley says: ”The Ad tired, I suppose, cut short the discussion by orderingI declined to do, and, as Rastignac, in the _Pere Goriot_, says to Paris, I said to London, _ nous deux_” This light phrase conceals a courageous and momentous decision He was absolutely without private resources, and having abandoned his professional work he had no salary of any kind For a year or so he supported hi reviews and popular scientific articles, striving all the tiain his bread but to continue his scientific work and et a professorshi+p of physiology or of comparative anatomy, and as vacancies occurred he applied, but unsuccessfully At the same time, he tells us, he and his friend, John Tyndall, were

”candidates, he for the Chair of Physics, and I for that of Natural History in the University of Toronto, which, fortunately, as it turned out, would not look at either of us I say fortunately, not from any lack of respect for the University of Toronto; but because I soon made up my mind that London was the place for me, and hence I have steadily declined the inducements to leave it which have at various times been offered”

In these early years in London Huxley's as e number of anonymous articles by him appeared in the _Literary Gazette_, and in other periodicals He assisted to relish scientific work by translating n memoirs With the collaboration of Mr Henfrey, he edited a series of scientific es, and e Busk he reat treatise on e part in the developy He made some valuable contributions to Todd and Bowman's _Cyclopaedia of Anatootten and practically superseded, but which was the standard anatomical work of the ress rapidly with his work upon oceanic Medusae, as he was uncertain how to have it published; the Adthy for publication in the volumes of the learned Societies As a matter of fact, he did not publish it until 1858, when it appeared as a separate memoir To the _Quarterly Journal of Microscopical Science_ and to the _Transactions of the Royal and Linnaean Societies_ he contributed a large nu with the microscopic anatoave a series of addresses at the Royal Institution, which had been founded as a ive accounts of their work to London society Abstracts of these lectures are published in the early volus of the Royal Institution_ and are interesting as shewing the kinds of zoological subjects which were attracting the attention of Huxley and which he considered of sufficient interest and ieneral public The first of these lectures, and probably the first given in public by Huxley, occurred on April 30, 1852, and was entitled ”Animal Individuality”

The problem as to what is meant by an individual had been raised in his mind by consideration of many of the foruesechains often th He explained that the word _individual_ covers at least three quite different kinds of conceptions There is, first, what he described as arbitrary individuality, an individuality which is given by theconsidered Thus a landscape is in a sense an individual thing, but only so far as it is a particular part of the surface of the earth, isolated for the ti at it If the observer shi+ft his position, the range of the landscape alters and beco else Next there are s, such as crystals or pieces of stone; and, lastly, there are living individuals which, as he pointed out, were cycles All living things are born into the world, grow up, and die, and it was to the cycle of life, froave the name individual In a si this plain definition of individuality; but Huxley went on to couese man-of-hich really is composed of a colony of Hydra-like creatures, the differentmore or less altered to serve different functions All these have cole si, and to the whole colony Huxley gave the naive a still wider interpretation to this view of individuality The original salp produced froives rise to many salps, whichaway from one another, may live separately Huxley extended the use of the word _individual_ so as to include as a single zoological individual the whole set of creatures cohering in chains or breaking apart, which had been produced by budding fro-cell This subtle analysis of ideas delighted and interested his conteical examination of what is meant by individuality has persisted to the present tiical ideas, this has been considerably altered by the conception of evolution Zoologists no longer atteical conceptions until they fit enornise that the living world, because it is alive, is constantly changing, and that living things pass through different stages or kinds of individuality in the course of their lives A single egg-cell is one kind, perhaps the sirown up into a sirade of individuality; when, by budding, the polyp has becorade is reached, and when the branches have become different, in obedience to the different purposes which they are to serve in the whole corade is reached Huxley's atte for individuality that would apply equally to a single sie nu froular capacity for bringing apparently dissi principle, and, although we no longer accept this particular conclusion, we cannot fail to notice in it the peculiar powers of hisRoyal Institution lecture dealt with the ”Identity of Structure in Animals and Plants” At the present time every educated person knows that the life of animals and plants alike depends on the fact that their bodies are co material called protoplasm, a material which is identical in every i world In the early fifties, scientific opinion was by no means clear on this ue Huxley discussed as anisation, and shewed that in every essential respect plants and anis Then he went on to explain the cellular theory of Schwann, which was then a novelty to a general audience Schwann, in studying the microscopic structure of plants, noticed that their bodies were made up of little cases with firm walls; these he called _cells_, and declared that the whole body of the plant was composed of cells As the walls of these cells were the most obvious and visible feature, it was supposed that they were the most essential part of the structure, and there was so the cellular theory to the bodies of animals, as in most cases there are no easily visible cell-walls in animal tissues As the result of his own observation, and fro of the work of others, Huxley laid down in the clearest hat is now accepted by everyone--that the presence of walls is of minor importance, and that it is the slimy contents of the cells, what is called ”protoplasm,” that is the important element He declared that the protoplasm of animals was identical with the protoplasm of plants, and that plants were ”anireed with Schwann that the cell, using the term to imply the contents rather than the wall, was of fundamental importance, and was the unit of structure of the whole world of life On the other hand, he declared that it could not be looked at as the unit of function: he denied that the powers and properties of a living body were sile cells In this opinion he was not followed by physiologists until quite recently For ists held that cells were units of function just as much as they are units of structure; but in the last ten years there has been a strong return to the opinion of Huxley

In 1851 two very important memoirs were published in the _Transactions of the Royal Society_, which contained the results of Huxley's observations of the interesting aniins as follows:

”The Salpae, those strange gelatinous anireat ocean soreat controversy since the time of the publication of the celebrated work of Chamisso, _De Animalibus Quibusdam e Classe Vermium Linnaeana_ In this work there were set forth, for the first tiular phenomena presented by the reproductive processes of these ani then known to occur in the whole province of zoology, that Chamisso's admirably clear and truthful account was received with almost as much distrust as if he had announced the existence of a veritable Peter Schle to Chamisso, salps appeared in two forms: solitary forms, and for chain

Each salp of the aggregate for nutrition from the mother by a connection similar to the placenta by which the embryo of a mammal receives nourishrow up into the solitary forregate form which developes in the interior of the body Charess to the develop,” he said, ”caterpillars did not bodily change into butterflies, but by a process of sexual breeding produced young which grew into the ordinary adults, and that these adults, as indeed they do, gave rise to caterpillars by sexual reproduction, then there would be a true alternation of generations”

The first generation would give rise to a second generation totally unlike itself, and this second generation would reproduce, not its kind, but the first generation; such an alternation of generations he stated to occur a the salps Huxley had an excellent opportunity to study this question at Cape York in November, 1849 ”For a ties of growth, and of size very convenient for exaeneral truth of Chaives rise to the solitary salps, and the solitary salps always give rise to chains of the aggregate salps But the process of reproduction he shewed to be quite different in the two cases The solitary salp produces in its interior a little stolon or diverticulurowth froradually becoate forate form are therefore merely buds from the solitary foreneration On the other hand, each salp of the chain has within it a true egg-cell This is fertilised by a male cell, and within the body of the parent, nourished by the blood of the parent, grows up into the solitary forenerations, but there are not two sexual generations The sexual generation of chain salps gives rise to forms which reproduce by buds

Froreed, Huxley went on to his theory of individuality Different naiven to the two forical individual; they were only parts of individuals or organs, and the true individual was the co both for ation of the structure of Salpa On one occasion only the _Rattlesnake_ came across a quantity of an allied Ascidian, Pyrosoma, which had received its name from its phosphorescence