The science of life : fully illustrated in tone and line and including many diagrams

INTRODUCTION

and so on to the subtle and ingenious analysis of all this ordered accumulation of facts and relationships.

Experiment has gone on from the seventeenth century, and since the middle of the nineteenth it has become the leading strand of biological work. Before that there were trials of this or that substance or device upon a living subject, vivisection to test deductions from observations, and a certain amount of exploratory experimenting, but there was no wide progressive continuum of experimental work. In the middle of the nineteenth century the Abbé Mendel made a series of breeding experiments, the full importance of which was not recognized at the time. The work was revived about the beginning of the present century and became the starting-point for a great activity of experimental breeding of poultry, rabbits, mice, guinea-pigs, flies, and plants of many sorts, types which reproduce with sufficient frequency to make possible the observation of a series of successive generations. Work upon the living subject became more and more frequent and relatively more important. Increasing delicacy of manipulation, particularly under the microscope, has, for example, rendered directive interference with the development of the eggs of many creatures a practicable thing, and much work has and is being done upon detached fragments of still living tissues, carefully kept alive in nutritive solutions, and upon the grafting of tissue from one organism upon another. As the task of observing, classifying, comparing, and recording the forms of life approaches completion, experiment will become more and more the normal method of progress.

Antagonism to biological knowledge is by no means dead. There is a constant struggle to keep physiological or pathological information from people who might put it into beneficial practice, and to prevent the complete discussion of such questions, for example, as the possible control of the pressure of population upon the reserves of the community. There is little or no reasoned justification for these suppressions. In some of the more backward regions of the United States, moreover, there is a formidable campaign for the penalization of any biological teaching that may seem to run counter to the literal interpretation of the Bible. A more intimate and dangerous attack upon biological progress is the sustained agitation to forbid experimentation upon living animals for scientific ends. Such experimentation is very rarely painful; in

14

most civilized countries it is carried out under conditions that ensure its restriction to sane and intelligent operations, and the necessary publication of its results is a guarantee against any possible abuse of the confidence reposed in the investigators. The word “ vivisection”’ is itself an unfortunate one. It intimates the cutting up alive of a sensitive, terrified, and helpless animal, and that never occurs. The “ antivivisectionists,’ however, wrung by the horrible suggestions of the word, do seem to believe, in spite of all evidence to the contrary, that this is the normal method of experimental biology and the anti-vivisection campaign displays all the unscrupulous exaggerations natural to tender and imaginative minds tormented beyond any possibility of patient and sober judgment. The older descriptive work in biology, based only on collection, classification, and anatomy, seems to be unlikely to achieve much more without co-operation with more modern branches of research.

Meanwhile a new province of observational and experimental work, ecology—the observation of animals in their proper surroundings and of their normal interaction and ways of life, and what one may call field physiology—is being very extensively developed. Men of intelligence are taking cameras and building watching-shelters in forest and jungle and prairie, where formerly they took gun and trap and killingbottle. Zoological gardens are being reconstructed and enlarged, so that, while formerly the animals were exhibited as specimens, they are now watched going about their normal affairs.

In place of the encyclopedic zoological gardens of yore, placed often in the proximity of great cities, with their smoky air and

‘abundant contaminations, governments are

now setting up reserves and small stations, here, there, and everywhere, in which particular species and groups of species may be observed less for structure than behaviour. This sort of observation passes insensibly into experiment—experiments in behaviour, experiments upon habit and intelligence, experiments in physiology. Parallel to these modern zoological gardens, the modern botanical garden expands from the old obsession with specimens. ‘There are now even bacteriological zoos, so to speak, where collections of living cultures of this, that, and the other infection are available for the experimentalist. Human psychology has also become observational and analytical in the past quarter of a century