Probably there were always lovers of the marvellous and the occult who favoured and would favour to-day the tradition of the conversion of one animal into another and such wonders; and there were also both in the days of ancient Greece and Rome, and even in the darkest of the Middle Ages, men with a sceptical and inquiring spirit, who accepted no traditional testimony, but demanded, as the basis of their admitting something unlikely as nevertheless true, the trial of experiment and the examination of specimens. What has happened since Gerard's time and the incorporation of the Royal Society in 1662, is that the sceptical men have got the upper hand, though not without much opposition. In this country, owing to the defective education administered in our public schools and older universities, there is still quite a large number of well-to-do people ready to believe in any "occult" imposture or fantasy that may be skilfully brought to their notice. On the other hand, we must bear in mind when we consider these strange beliefs held by really learned and intelligent men in the past, that the investigation of nature had not advanced very far in their time. It was not held, as it is to-day, as an established fact that living things are generated only by slips or cuttings of a parent or from eggs or germs which are special detached particles of the parent. It was held to be a matter of common observation and certainty that all sorts of living things are "spontaneously generated" by slime, by sea foam, by mud, and by decomposing dead bodies of animals and trees. It was also held, in consequence of a blind belief in, and often a complete misunderstanding of, the legends and fairy tales of the ancients and of the preposterous "Bestiaries" and books on magic which were the fashion in mediaeval times, that it is quite a usual and natural thing for one animal or plant to change into another. Hence there was nothing very surprising (though worthy of record) in a barnacle changing into a young goose, or in the buds of a tree becoming in some conditions changed into barnacles! So, too, the notion that rotting timber can "generate" barnacles was not, to our forefathers, at all out of the way or preposterous. Sir Thomas Browne in 1646 was unable to make up his mind on this matter, and believed in the spontaneous generation of mice by wheat, to which he briefly alludes in his curious book called "Pseudodoxia Epidemica, or an Enquiry into Vulgar and Common Errors." The account of the creation given by the poet Milton was based upon the belief in the daily occurrence of such spontaneous generation of living things of high complexity of structure and large size, from slime and mud. The process of creation of living things conceived by him was but a general and initial exhibition of an activity of earth and sea which in his belief was still in daily operation in remote and undisturbed localities.