Dr. J.M. Wilson then took the chair in place of Mr. Kirk who read a paper – the sixth in a series – on “The Lower Forms of Animal Life”

In the course of his paper, which dealt with specimens found in this district, he said that if they collected a small portion of the vegetation which was found at the surface or sides of a pond, as well as some of the clear water, it would always be found to contain many living things; some just visible to the naked eye, whilst others would require to be greatly magnified before they could be detected.

It was commonly supposed that foul and stagnant water contained the best collection of living objects for the microscope, and most hunters after this minute life would have had a dip of an unsavoury and uncanny-looking mixture offered to them as being sure to afford something worth looking at. In point of numbers that sort of water might gain the day, but it only abounded in the commonest and what they might call most insignificant forms of life, extending no higher in the scale than paramecium aurelia.

The purer the water the higher the form of animalculae they would find, and the most beautiful and most prized kinds were almost without exception found in the sweetest water. It was his intention to deal with those forms of life which he  had himself found in this neighbourhood, and he  might say that Doncaster was considered by microscopists in other towns to be a most advantageous hunting ground, and he had twice when away from home, on admiring some fine specimens, been told that it was obtained at or near this town.

On referring to their glass of water freshly drawn from a pond they would see the higher living things mostly I rapid movement about the water, whilst some clung to the small plants and weeds. They were usually small crustacea and also the larvae and active nymphs of insects. Sometimes a water spider was included, and often small wriggling worms were to be seen. But the most numerous dwellers in the water were either in a few instances just visible to the naked eye or were to be seen in countless numbers with the aid of high magnifying powers under a compound microscope – some single drops of water containing a greater number of life than our world has inhabitants.

A discolouration of water might sometimes be noticed, which was caused by the presence of crowds of microscopic, or nearly microscopic animals, which were called animalculae, or little animals, and also infusoria, or animals which live in infusions. In water which might be icy cold or very warm, and in water which was impregnated with foetid gas and decaying animal and vegetable remains, these simple, active, wandering, or sedentary microscopic creatures, which constituted the lowest form of the animal kingdom, and which in some instances were separable only in a very arbitrary manner from some members of the vegetable kingdom, might be found in abundance.

If lately-collected rain-water were examined in the hope of discovering any of the minute forms of life, they would be disappointed, but if some hay or any vegetable matter were allowed to soak in pure water exposed to the air, or if pieces of fish or any animal substance were placed in water and also exposed for a day or two, a great many species of these animalculae of infusoria, the individuals being in vast multitudes would be distinguishable.

Infusoria were discovered in all climes; they had been found 60 feet below the surface of the earth and in mud brought up from a depth of 1,600 feet of ocean. They existed at the poles and the equator, in the fluids of the animal body and plants, and in the most powerful acids. They did not find it easy to explain that the objects which swam about the water with apparently some small amount of will of their own belonged to the vegetable and not the animal kingdom. The axiom of Linnaeus was well known.

In the case of the higher animals and plants there was no difficulty – the former being at once distinguished by the possession of nervous system, of motor power which they could use at will, and of an internal cavity fitted to receive and digest solid food. The higher plants, on the other hand, had some of those qualifications. Those distinctions, however, did not hold good as regarded the lower and less highly organised members of the two kingdoms.

As to form and shape, no absolute distinction could be laid down, and this was also the case as to their internal structure/ Next, as to motor power. This, though broadly distinctive of animals, could by no means be said to be characteristic of them. As a rile, all plants were endowed with the power of converting inorganic into organic matter. On the other hand, no known animal had that power. Plants were the great manufacturers in nature, animals the great consumers.

It might, not unnaturally, have been thought that the lowest classes of animals would show the most affinity to the highest plants, and thus a gradual passage between the two kingdoms would be established. That was just what the evolutionist would like. It was not so, however. The lower animals were not allied to the higher plants but to the lower, and it was in the very lowest members of the vegetable kingdom that they found such a decide animal gift as the power of independent locomotion.

The lecturer referred to many different species of animal life, and the lecture, which was of a most interesting and instructive nature, was illustrated with 60 drawings and objects shown under the microscope.