Abstract
AT the early age of thirty-nine, one of the most skilful, laborious, and honoured of European zoologists has been lost to Science in the person of Edouard Claparède. For the last three years his health has been such that his friends continually feared to receive the sad news which has at length come from Italy. In spite of a complication of pulmonary and cardiac disease, his indomitable spirit had kept the man at work to the last. Having taken up his residence in Italy for the benefit of his health, he produced during the last three years of his life a series of memoirs, so richly illustrated, and exhibiting such astonishing industry, that one would have fancied a man in full health and vigour was unequal to such abundant fertility. He once remarked to a friend, who expressed surprise that a man in his precarious state of health should work so hard, that he felt work was the only thing which kept him to life, if he left off working he should die at once. Claparède was a. native of Switzerland, and a pupil of that great master of great zoologists, Johannes Müller. He could write French and German equally well, and consequently some of his researches are to be found published in the German periodicals, others in French in the Transactions of the Academy of Geneva. His earliest published work of large size is the “Recherches sur les Infusoires,” which he produced in conjunction withhis friend Lachmann, who unhappily died before it was completed. Though now to a great extent superseded by the later researches of Stein, Zenker, Cohn, and others, working with more accurate instruments, this treatise is one of classical importance, and forms the foundation of modern views on the Infusoria. Not long after the publication of this work, Claparède came to England, where he made the acquaintance of Dr. Carpenter, and spent a portion of the summer in his company in the Hebrides, working with the microscope, chiefly at the lower worms and annelids. From this expedition resulted a quarto publication, illustrated with plates (published by the Geneva Academy), giving accounts of new marine worms allied to the Earth-worms, and many valuable observations on the Turbellarian worms. In conjunction with Dr. Carpenter, he also published some observations on the curious Tomopteris onisciformis in the Linnean Transactions Attracted by the Limicolous Annelids, Claparède continued his observations on the forms of this group inhabiting the streams around Geneva; and his “Recherches sur les Oligochêtes,” also published by the Geneva Academy, furnished zoologists with a very complete account of the anatomical and systematic differentiæ of many of these worms, till then almost entirely neglected and. misunderstood. In this work the homology of the segmental organ with the reproductive ducts was demonstrated. The circulation of spiders, which he studied in the transparent young of the genus Lycosia, and the development of the freshwater gasteropod, Neritina fluviatilis, also about this time furnished occupalion for his pen and pencil; and an elaborate work on the development of the Nematods, in which the important questions of the signification of the parts of the egg are discussed, was completed by him. In the collections of miscellaneous observations, always finely illustrated, which he from time to time published, such as “Glanures zootomiques,” “Beobachtungen über wirbellosen Thiere,” &c.,“he recorded observations principally on the Annelids and free-living worms, which he made from year to year on the coasts of Normandy or the shores of the Mediterranean, and many strange forms, paradoxical marine larvae, and unsuspected annectant genera, are briefly figured and described, which excite the interest of the zoologist, and awaken the desire to know more of them; whilst in other cases new modes of reproduction, new anatomical details, or physiological observations are related (for Claparède was no narrow zoologist) of rare and little known forms. The great work which he took in hand after his health had compelled him to reside in a warm climate during winter, was the study of the Annelids of the Bay of Naples. Under this title he has left two thick quarto volumes, illustrated by more than fifty coloured plates, consisting of anatomical and enlarged coloured drawings of these beautiful worms. Many new and curious forms were added by one winter's work to the known species of the Annelida; but his work is even more valuable for the anatomical and histological observations which are there recorded, and for the great critical ability displayed in dealing with the perplexing questions of synonymy. M. Claparède appears to have found especial pleasure in doing justice to Delle Chiaje, who preceded him in the investigation of the fauna of the Bay of Naples; whilst he does equal justice to M. de Quatrefages, whose errors in a recently-published “Histoire des Annelèes” he does not hesitate repeatedly in the course of his book to expose, at the same time dedicating the first volume of his work to that distinguished French naturalist,and naming many new species in his honour. Whilst this splendid work on the Neapolitan Annelids was in press, M. Claparède also gave to the world some very interesting studies on Acarids (published in German), in which many new facts are detailed, and the Darwinian theory, in the manner of Fritz Müller, is shown to furnish a satisfactory explanation of the modification of dissimilar parts in different genera, to form identical organs. During the same period he also published in the Zeitschrift für wiss. Zoologie a memoir on the histology of the Earth-worm, illustrated with nine coloured plates, which is certainly the most minute and careful piece of work which he ever produced. The structure of the nervous system and of the three “riesige Rohren-faden,” soon to become very celebrated in zoological circles, are here for the first time fully described; and, indeed, the subject had been so slightly, handled before that the whole work abounds with new matter. M. Claparède's last published paper appeared this year in the Zeitschrift, and as if to show that he did not intend to abandon himself to the study of one group, consisted of observations on the anatomy and reproduction of some marine polyzoa, illustrated by three coloured plates, drawn with his accustomed facility and grace. He has, we understand, left behind him ready for publication a large work on the Embryology of Insects, and an immense collection of microscopic preparations, of Annelids of great value. Perhaps the most striking discovery recorded in any of M. Claparède's writings (which should, however, be judged by the accumulated value of their immense number of anatomical observations) is one among those relating to the Annelids of the Bay of Naples. Claparède found that the Nereis Dumerilii lays eggs, sexually fertilised, which, on hatching, produce a worm which had been placed in quite a distinct genus (Heteronereis), and this worm lays similar true eggs, which produce sometimes a second kind of Heteronereis, or at other seasons the original form Nereis Duvierilii again. The difference between Heteronereis and Nereis is very great, and one extending into such details as the form of the seta; of the feet. At present this appears to be the only real case of alternation of generations on record, if, by “generations,” we understand “sexual generations.”
Article PDF
Rights and permissions
About this article
Cite this article
L., E. Edouard René Claparède . Nature 4, 224–225 (1871). https://doi.org/10.1038/004224c0
Issue Date:
DOI: https://doi.org/10.1038/004224c0