Leonard Jenyns, Vicar of Swaffham Bulbeck©17 July 1999, John H. Wahlert
Leonard Jenyns, brother-in-law of John Henslow and Vicar of Swaffham Bulbeck, Cambridgeshire (1828-49), was a country parson whose avocation was entomology. He led the kind of life that Charles Darwin may have envisioned for himself as a clergyman.
Darwin and Jenyns met, when Darwin was an undergraduate at Cambridge, and the two of them collected insects, especially beetles, together. Jenyns was born in 1800 and was thus about 9 years older than Charles Darwin. He has been recommended as FitzRoy's companion and naturalist on the Beagle voyage, but parish responsibilities prevented his acceptance (Moore, 1985: 445).
Charles Darwin (1958: 66-67) wrote of Jenyns:
Jenyns said of Darwin (web page by Roger Vaughan of Jenyns' original text):
Jenyns published works include A Manual of British Vertebrate Animals, an edition of The Natural History of Selborne by the late Rev. Gilbert White, Observations in Natural History, and fishes of the Beagle voyage. White's Selborne was the model for nature observation that Darwin read and enjoyed and which Jenyns copied by presenting his own observations in the book quoted extensively below. How much of this had Jenyns communicated to Darwin, if any, when they collected insects? Jenyns provides a model of both the observer of nature and the synthesizer and theoretician that Darwin would become.
Further information about Leonard Jenyns is available on the web site of Roger Vaughan, who has collected a vast archive of Jenyns materials and is the author of a rich and growing web resource.
PREFACE: "...He [the author] is disposed to hope that this volume may also have its influence in tending to increase the number of observers; that it may help to put those, who are much abroad, or who are otherwise favourably circumstanced in this respect, into the way of collecting, and entering in a daily journal, such little facts as may offer themselves to their notice, and which, under the guidance here afforded them, they may deem worthy of record."
Excerpts from the Introduction on Habits of Observing:
(1.) Natural History has been said by some to be a study of facts; by others, a science of observation. Each of these statements is to a certain extent true: it is only by observation that we can acquire a knowledge of the facts upon which all ulterior views must be based. But neither does this, nor any other science, rest satisfied with the bare recording of isolated and independent phenomena. It seeks to classify these phenomena, and to comprise them within certain general principles, established by inductive reasoning, to the influence of which they may all ultimately be referred. Doubtless this is taking an extensive view of the subject, and, when we contemplate the immensity of nature, entering upon a field which it may require years to travel over, and which we may never be able to measure in its full dimensions. Yet that there are such principles as we allude to, is next to certain. Looking only to the analogy of other sciences, we might predicate their existence; when, however, we regard further the frequent attempts which have been made of late years to discover and fix them, and the present aspect of the science compared with what it exhibited a century or two back, we can hardly entertain a doubt on this point. And though we may never attain to a complete knowledge of them, they form as it were the main aim and object of the science, to which the labours of the scientific naturalist are ever directed, and to which at least he makes a nearer advance, the more he investigates the relations existing among the various matters that present themselves to his notice. (p. 3-4)
(4.) But further; it has happened in most sciences that the collecting of facts, and the deducing from them any such important generalizations as may lead to a comprehensive theory, have been the work of different individuals. In sciences, indeed, which have made any considerable advance, such division of labour becomes unavoidable. The observer, therefore, need not be discouraged, because he is not possessed himself of those attainments necessary for proceeding to the investigation of such principles as his observations may assist in establishing. He may leave this to others, and content himself, if he will, with a more subordinate part. And in Natural History especially it is almost necessarily the case that the observer and theorist should be in some measure separated. For the facts here required are of such a kind as cannot all be procured at will, or in any situation we please. Many of them call for opportunities of a very peculiar nature; and those who enjoy such opportunities are not unfrequently, by that very circumstance, shut out from making any application themselves of the knowledge they have acquired to the furtherance of the general interests of the science. (pp. 5-6)
(5.) That we may see this the more clearly, let us stop to take a general view of the descriptions of facts which are wanted by the naturalist to enable him to proceed in his inquiries into the general principles upon which Nature seems to have based her system. For this purpose he must have under his view all the different species and varieties of animals with which this earth is peopled; and he ought to be able to inspect them, not merely in the dead or preserved state, but in the living or at least recently-killed... etc. (p. 6-7)
(6.) ..."There is a great deal, as regards the real advancement of the science of Natural History, which can be done only at home, where there is quiet and leisure, together with ready access to a well-stored library; and there is a great deal likewise, as we have just seen, that can be done only abroad... (p. 8)
(14.) The habit we are here recommending is peculiarly adapted to a country life; and, in the pleasures which it affords, offers a full compensation for the loss of those advantages, which are only to be reaped in the society of large towns... (p. 20)
(15.) As a further encouragement to the forming a habit of observing the works of Nature, we might mention, what has been so often alluded to, its tendency to foster, if not to generate, a devout turn of mind towards their adorable author. Undoubtedly it has this effect, where there is no perverseness or viciousness of temper present to counteract it. In watching the habits of animals, and the provision made for their welfare and happiness, in noting their varied instincts, their arts and stratagems to obtain the necessary support for themselves and young, their mode of defending themselves against their enemies, and all their ways so replete with matter for reflection and astonishment, we cannot but trace the finger of their Great Creator: we cannot but consider all we see as affording the clearest indications of His over-ruling Providence. It speaks to the existence of some mighty Power, whose secret influence upholds order and harmony, amid what would otherwise be a chaos of confusion and turmoil, from the conflicting interests of so many different agents... (21-22)
(17.) Before we quit this part of our subject, it may not be improper to make one remark as a caution necessary to be impressed on some observers. Good and excellent as are the feelings towards the Creator, which the study of Nature is calculated to produce within us, we must not attach so much importance to them, as may lead to the exclusion of other considerations of far higher and weightier moment. In other words, we must not mistake natural religion for revealed; nor suppose that the truths, which this last alone can teach us, are to be learnt by the most attentive regard to this lower world and its varied productions. This is a solemn reflection, which it would be out of place to follow far here. And we simply allude to it, from our belief that there are some naturalists, who make their study of the works of the great Creator the whole of their religion, and the sense they thereby attain of His adorable perfections a plea for neglecting the teaching of His revealed Word.- May we never forget, that both these come from the same author;- that manís welfare and interests are as much concerned and bound up in the one as in the other;- and that no feelings are to be trusted, which prompt us to make our own selection, in respect of what is to be our rule of duty or our guide to happiness. (p. 27-28)
[The following two items struck a chord with me, as they seem as true today as in the 1800s.]
(21.) But besides being carried away by first impressions, we must carefully guard against being influenced by prejudices. And such prejudices as are likely to interfere with correct observation are of two kinds. We may be prejudiced by popular notions, which have been long and generally entertained, and which are originally due either to ignorance or superstition; or by a bias affecting our own minds individually, and caused by a peculiar train of thinking into which we have fallen...(33-34)
(22.) The second class of prejudices above alluded to are not those of an uneducated mind, but of one that has been warped by long reflection of a peculiar train of ideas. Under such circumstances, the observer sees everything through a distorted mirror. His usual habits of thinking interfere, and mix themselves up, with the impressions of the senses, substituting, in many cases, a false image for the true one. Nothing is noticed but what bears upon the favourite matter of speculation; or, if observed, it is not observed in its proper colours, and often, when the mind is on the search for novelty, it is so full of a preconceived idea, that it fancies it sees what has no existence in nature. This is too frequently the case with those naturalists who have some theory to maintain, and who seek to uphold and confirm their particular views by an appeal to facts. Everything appears to fall in exactly with their preconceived notions...(p. 35.)
Darwin, Charles. 1958. The autobiography of Charles Darwin, 1809-1882. Barlow, Nora, ed. W. W. Norton & Company, New York. 253 pp.
Jenyns, Leonard. 1846. Observations in Natural History. London: John van Voorst. 440 pp.
Moore, J. R. 1985. "Darwin of Down: The evolutionist as squarson-naturalist." Pp. 435-481 in D. Kohn, 1985, The Darwinian Heritage, Princeton Univ. Pr., Princeton. Jenyns was one of three fellow scientists (also Hooker and Lyell), in who Darwin confided his growing belief that species change through time.Vaughan, Roger. 1999 Roger Vaughan's Jenyns pages home page.
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