DR. CARPENTER ON THE "FORAMINIFERA."* WE have before us in
elaborate memoir, by one who may justly be characterised as the most cautions and philosophical of the biologists of our time. All who take an interest in biology know how devotedly Dr. Carpenter has, studied the phenomena of life, from its lowest and simplest forms to its highest and most complex. This memoir, which is supple- mentary to several previous monographs on the same or allied groups of organisms, was read before the Royal Society last year. Its tone is Darwinian,—that is to say,
• Researches on the Foraminifera Supplemental Memoir. By W. B. Carpenter, C.B., M.D., LL.D., F.R.S. From the "Transactions" of the Royal Society. Part IL less.
the author's object is to trace what he considers the succes- sive steps in the evolution of a certain type of the curious little
marine organisms known as Foraminifera. To convey to our
readers a distinct idea of the details of this paper would involve an amount of technical discussion unsuited to these pages, and would be almost impbssible without the use of diagrams; but there are certain general principles which seem to ne of great importance in relation to biological science, and having, indeed, some bearing on what we may call the general philosophy of all science, of which this little memoir on a most obscure and little-known part of the organic universe gives us a glimpse. Many of our readers will ask, "What is an Orbilites ?" and "What are the Foraminifera f"' We think we can make them understand something of these things, and also show how im- portant a bearing their study, and that of equally humble crea- tures, may have on the physiology of man and the higher animals,—a branch of science which nobody can pretend to look upon as frivolous.
The Foraminifera are a group of beings of almost the lowest rank in the organic scale, inhabiting the ocean in immense numbers, and, their exuvite or remains form beds of vast extent and depth in the Atlantic. Their structure is very re- markable. Most of them consist, individually, of little more than a small mass of protoplasmic substance (" sarcode," it is commonly called), homogeneous or nearly so, having no parts, no limbs or stomach, blood-vessels, muscular fibre, or nervous system ; yet endowed with the power of motion, motion by the mere stretching out of portions (any portion, in- discriminately) of their own substance, and presumably endowed with some dim form of consciousness. Though thus simple in their own structure, if structure it can be called, they have the power of secreting a shelly covering, often of great beauty and some complexity. Through certain little holes (whence the name," Foraminifera") in these shells, the creature can push or cause to overflow portions of its own substance, apparently for the purpose of -imbibing nourishment, or other- wise coming into contact with the world outside of its shell. These organisms are very various in the form and structure of their shells, though all falling under the general description we have just given, and have been divided by naturalists into many genera and specie i Dr. Carpenter, in this paper, shows the gradual evolution of the more complex types from the simpler forms; how chamber after chamber is added to the shell as the creature developes, so that a gradual transition, which he hypothetically sketched out in his previous papers as the probable pedigree of some of the forms, can now be shown in actual fact during the successive stages of the growth of the new type which is the subject of the present brochure. It is, of course, impossible to convey the details of all this, but any of our readers who has sufficient in- terest in such matters may find much delight in the study of the memoir itself, and the admirable diagrams of the shells and sections of them. In most of them he will be struck with the wonderful similarity of form of their structure to the shells of creatures immeasurably higher in the animal scale, the tribe to which the familiar mollusk known as the Nautilus belongs.
One of the most curious facts brought to light by Dr. Carpenter is this. - If a . well-developed individual of the Orbitulites tenuissima, a most beautiful and delicate _struc- ture, receives a mechanical injury so as to break the fragile calcareous substance which forms one or more of the chamberlets into which its shell is subdivided, the simple• protoplasmic. matter which forms the animal itself, the very lowest type of living substance, reproduces the shell and repairs the fracture exactly as the special part injured previously existed,—this process, be it observed, being on a plan totally - different from the process by which this same little mass of sarcode began its life and formed its &rst shelly envelope, before the successive chambers were added, as it grew larger. The homogeneous substance is thus .shown to be endowed with forces which adapt themselves to circumstances, and there is offered a pregnant instance of a "law of formation," laid down by Sir J. Paget in regard. to higher and more complex organisms. In his Lectures on Surgical Pathology, he says :—" When, in an adult animal, a part is reproduced after injury or removal, it is made in conformity not with the condition which was proper to it when it first formed, or in its infantile life, but with that which is proper according to the time of life at which it is re- produced; proper, because like that which the same part had, at the same time of life, in members of former generations." This remark was made long before the doctrine of evolution was heard of, and it is an admirable illustration of the golden rule that the primary laws of biology can best be investigated by the study of their action in the simplest and least complicated orders of beings, where we. have those laws acting, so to speak, in -their purity, undisturbed by other principles of action. As these minute and most interesting creatures rise, within their own tribe, in beauty and complexity, it is of great importance to observe that the development, so far as we can discover, con- sists entirely in greater specialisation of the shelly covering, the living creature itself, except in one or two very trivial par- ticulars, remaining without any progressive complication of parts, or any structural modification suggestive of variety of function. This proves that there is, in protoplasm, some latent force or forces capable of originating any one of many results, according to the necessity of the case, the protoplasm itself being apparently unaltered, and the surrounding circumstances, though peculiar in each instance, not such as to give any apparently sufficient cause for. the 'diversity of result. The bearing of this on more complicated processes in other quarters is obvious.
Another important remark made by Dr. Carpenter in reference to his "Theory of Descent with Modification" in this group or organisms is made in these words :— "Those who find in natural selection,' or the survival of the fittest,' an all-sufficient explanation of the origin of species,' seem to have entirely forgotten that before natural selection' can operate, there must be a range of variated forms to select from ; and that the fundamental question is (as Mr.. Darwin himself clearly saw, at any rate in his later years), what gives rise to variations? No exercise of natural selection' could produce the successive changes presented in the evolutionary history of the typical Orbilites, from Cornuspira to Spiralocnlina, &c. As all these earlier forms flourish under conditions which (so far as, can be ascertained) are precisely the same, &ere is no ground to believe that any one of them is better fitted to survive than another. They all .imbibe their nourishment in the same mode ; and no one type has more power of going in search of it than another?' Nor is there any reason to suppose that the higher development can escape from its natural foes any better than the lower. The differences in structure are, we must remember, by no means trifling, as they represent progress from "a simple, spirally-coiled sarcodic conch, to a dish-shaped .body with thousands of sub-segments disposed with the most perfect symmetry, and connected together in the most regular and uniform modes."
Everything shows a progressive tendency along a definite line, so far as the calcareous shells are concerned, without the animal body departing from its sameness. The extreme fulvo- dates of the Evolution hypothesis may take a hint from this memoir, that though the survival of the fittest is undoubtedly a factor in the progress of organic life, it is only one of many, and that there are more principles and causes in operation than are dreamt of their philosophy.
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