The Microscope and its Misinterjpretations. By J. Michels. 55 
few montlis the Podura headings, such as he described them, will be 
fully estabhshed. 
Thus was the gauntlet thrown dowD, and the challenge was at 
once accepted by various members of the Society, who, on the con- 
clusion of the reading of the paper, at once disputed the 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. 
Pigott in error ; he had never seen such appearances as beads ; 
thought probably Dr. Pigott had seen them by using too deep an 
eye-piece, bad illumination, and drawing out the tube of the micro- 
scope to too great an extent ; or, perhaps, to a disturbed vision 
caused by advanced age and presbyopia. 
The President, the Eev. J. B. Eeade, 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. Pigott 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 mi- 
croscopical research, is always listened to on this subject with 
respect by the Society, having devoted his attention specially to 
these insects, and shown a patient and intelligent power of observ- 
ing not only their structure but their habits ; he, in his commu- 
nication, opposed Dr. Pigott '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 Eev. J. B. Eeade, stated 
that he, with Dr. Miller and others, had interviewed Dr. Pigott, 
and was bound to say he had seen the beaded appearances, and it 
was clear to hird now that in the best object-glasses small residuary 
aberration existed. 
This slur upon the best object-glasses brought out Mr. Wenham 
with a paper in the Microscopical Journal of June, 1870, in which 
he repudiated such error, and described the beaded appearance as 
an illusion, obtained by a trick of illumination, and by examining 
the scale with the microscope out of focus. 
At the June meeting of the Eoyal Microscopical Society a 
letter was read from Colonel Woodward, of Washington, enclosing 
photographs of the Podura scale, showing what he considered to be 
