240 PROCEEDINGS OF SOCIETIES. 



Mr. Slack handed in, and described briefly, tbe contents of a paper 

 he had written " On the Optical Appearances of Cut Lines on Glass." 



A paper by Mr. Chas. Cubitt, C.E., was then read, " On Linear 

 Projection considered in its Application to the Delineation of Objects 

 under the Microscope." 



Mr. Hogg said the Society was much indebted to Mr. Cubitt for 

 bringing before them the subject of his jiaper. It was hardly necessary 

 to say that to pui'sue the subject as he (Mr. Cubitt) had pursued it, re- 

 quired the special training of his jDrofession to carry it on successfully. 

 His labours would certainly tend to correct the imperfect drawings of 

 objects such as he had rej)resented, and which imperfection he (Mr, 

 Hogg) considered to be due in a measure to the objects being viewed 

 imder compressoriimis. It was nevertheless almost impossible to 

 make accui-ate drawings of living objects unless the movements of the 

 animal were somewhat restricted. He might refer to the drawings made 

 by Mr. Topping of the fly's tongue, and to the representations of many 

 other objects as an illustration of the effects of compression. So far as 

 his experience had gone, he had always been unable to use the camera 

 lucida for drawing microscopic objects ; and having had no training, 

 such as Mr. Cubitt had enjoyed in mathematical drawing, the repre- 

 sentations he had made he knew to be often imperfect. He had 

 also found, after repeated trials, that the ingenious instrument devised 

 by Mr, Cooke for making better drawings of living objects was of 

 very little use to him. He thought Mr. Cubitt would admit that not 

 only in the case of Melicerta ringens, but also of CEcistes, the disk of 

 these very interesting animals, consisting of a hollow sarcode or pro- 

 toj)lasmic structui'e, which was constantly undergoing changes of form, 

 made the work of di-awing them very difficult, and accounted for some 

 of the inaccuracies of published drawings. 



Mr. Slack said, with reference to the observation as to the change 

 of form which living objects displayed, if the creature, viewed under 

 the microscope, altered its dimensions, the fact should be mentioned, 

 and a front view or side view should be given on the principles of 

 perspective. 



A vote of thanks was then given to Mr. Cubitt, 



It was announced that at the next meeting a paper would be read 

 from Dr. Maddox, " On the Structui'e of Lepidopterous Scales, as 

 bearing on the Structure of Lepidocyrtus curvicollis ;" and also a 

 paper by Mr. B, T, Lowne, " On the Foot of Dytiscus." 



The Secretaries announced that some persons had been making 

 use of the late collector's card and name for the j)ui-pose of obtaining 

 subscriptions from the Fellows. The act was wholly unauthorized. 

 The only persons appointed to receive money on behalf of the Society 

 were Mr, Eeeves, and the Treasiu'er (Mr, Mestayer) ; and their 

 receipts alone were valid. This statement was not made for the pur- 

 pose of casting any reflection whatever upon Mr, Low, as the Secre- 

 taries did not believe that he would in any way give his consent to 

 such a proceeding as that which had been referred to. 



The meeting was then adjourned to the 3rd May next. 



