Abstract
The study of anatomy in its early days was confined, both by choice and tradition, I to man and the higher mammals. The outstanding workers in the prolonged and I uneventful period between Galen and Vesalius described only what could be seen with the unassisted eye. What lay beyond this restricted field was hardly conjectured. It was not until the sixteenth century that the anatomy of the lower vertebrates was attempted, principally by Rondelet, Belon, Coiter and Casserius, and not until the following century that the emergence of the microscope and the employment of simple magnifying glasses opened up avenues of investigation hitherto untrod. At this time also the invertebrates attracted the attention of the anatomist, who now began to ask himself whether the smallest animals might not reveal a much simpler or possibly even a novel type of organization. Was it reasonable, in fact, that an animal so small as almost to escape observation should nevertheless exhibit the same anatomical complex as the larger species of its group? Such a belief provoked the curiosity particularly of Malpighi and Swammerdam, who proceeded to put it to the test of observation. Hence micro-dissection came into practice, and was added to the more subtle technical devices of the anatomist. But smallness as such was not favourably regarded by the philosopher, who rejected its investigation as contemptible in itself and unworthy of the serious attention of mankind. Thus Malebranche, in his Search after Truth,* warns his scientific contemporaries, so we are told, that man was not made to contemplate midges. His actual words, however, are not quite as bad as that. What he says is that man was not made
only
to contemplate midges. Micro-dissection as now understood was developed as a cytological technique in the early years of the present century by Barber and Chambers, but the micromanipulators designed by them were constructed to explore the mechanism of individual cells, and were not suitable for the dissection of an entire animal, however small. Such equipment, indeed, can manifestly be modified with the latter purpose in view, and would ensure a greater steadiness and refinement of movement than can be achieved by the human hand alone, but the modern observer prefers to reconstruct the minutiae of anatomy by other means, such as powerful binocular dissecting microscopes, or modelling and plotting the details from serial sections on wax plates and squared paper. The art of micro-dissection is in fact commonly credited to the ingenuity of our own times, but it is my purpose to show that it was first accomplished, with a remarkable degree of accuracy, as early as the seventeenth century. The first naturalist to attempt this difficult feat was Malpighi, who produced a work on the mulberry silk moth which has established itself as the foundation of our modern knowledge of the morphology of the Insecta.* Happily we have in his own words a lively narrative of the trials of this enterprise. ‘In 1668’, he says, ‘I decided to rear in my house some silkworms of the species which produces cocoons three times a year, and by repeating my observations many times, with all the care of which I am capable, I was able to prepare a history in which I attempted to demonstrate not only the external development of the insect, but also the pattern and structure of its internal viscera. This was an occupation to the last degree laborious and fatiguing because of the novelty, smallness, delicacy and mutual confusion of the parts. Also it could only be accomplished by the employ ment of entirely new methods, and since I persisted in this exhausting task for many months without a break I was afflicted in the following autumn with fevers and inflammation of the eyes. Nevertheless, in pursuing these researches, which brought to my notice so many strange marvels of nature, I experienced a pleasure which my pen is unable to describe. I next combined the observations so obtained into a dissertation, which I sent with the drawings to the Royal Society of England at the beginning of the year 1669.’ The Society promptly recognized the importance of the work by admitting Malpighi to the fellowship on 4 March 1669. The imprimatur was signed by the president on 22 February and the book was published by the Society on 15 July, within six months of the receipt of the copy. The manuscript and original drawings are still available for consultation in the archives of the Society.