and concludes with the remark that he expects in a few months the podura headings, such as he described them, will be fully established.
Thus was the gauntlet thrown down, and the challenge was at once accepted by various members of the Society, who, on the conclusion of the reading of the paper, at once disputed the new doctrine. Mr. J. Beck was the first to express an opinion, and rather increased the confusion of the subject by stating that both the spines and the beads were illusory, and that the true structure of the podura-scale was a series of corrugations on one side, and that the reverse side was slightly undulating or nearly smooth, and that the notes of exclamation were due to refraction of light.
Mr. Hogg, the Hon. Secretary of the Society, thought Dr. Piggott in error; he had never seen such appearances as beads; thought probably Dr. Piggott had seen them by using too deep an eye-piece, bad illumination, and drawing out the tube of the microscope to too great an extent; or, perhaps, to a disturbed vision caused by advanced age and presbyopia.
The President, the Rev. J. B. Read, followed by stating that he agreed with the observations made by Mr. Hogg, and such was his faith in the skill of the opticians of the day, that he could not but feel that what he saw with their instruments really existed.
On the same date and occasion on which Dr. Piggott expounded his views, Mr. S. J. Mclntire, a member of the same Society, read a paper "On the Scales of Certain Insects of the Order Thysanura." Now, Mr. Mclntire, although a recent member, and young in microscopical research, is always listened to on this subject with respect by the Society,
Fig. 5.
having devoted his attention specially to these insects, and shown a patient and intelligent power of observing, not only their structure but their habits; he, in his communication, opposed Dr. Piggott's views, and calls the beads "optical illusions," and concurred with Mr. Beck's statement that the surface of the scale is corrugated, but flatly contradicts him by stating that both sides are alike.
December 8, 1869.—The President, the Rev. J. B. Read, stated that he, with Dr. Miller and others, had interviewed Dr. Piggott, and was bound to say he had seen the beaded appearances, and it was clear to
