QUEKETT MICROSCOPICAL CLUB. 107 



J. M. Allan, near Geelong, and subsequently by Mr. E. C. 

 Joshua. 



Replying to a question, the President said that formalin was 

 very unsafe to use in such cases, as it frequently becomes acid 

 after a short time. 



Mr. J. Burton said he took some of the material brought by 

 Mr. Whitteron, and, after some trouble, had found some 

 wheels in the skin. They looked as though acid had been 

 previously applied. The wheels showed a tendency to break 

 down into anchors, reminding one of the well-known Synapta 

 spicules. The anchor form, as the President had said, was an 

 early stage in the development of the wheel. The wheels, under 

 a, binocular, proved to be basin-shaped. There was a second 

 kind of spicule, something like a drawer- handle in shape, and a 

 third shape, found only in the tentacles, where it was very 

 numerous, constituting, perhaps, 50 per cent, of their bulk. 



The thanks of the meeting were unanimously voted to the 

 President for his communication. 



Several notes from Mr. E. M. Nelson were read to the meeting 

 by the Hon. Secretary, as under : 



1. "On Microscopic Construction and the Side-Screw Fine 

 Adjustment," in which he traced the history of this form from 

 1841 to the present time, with some suggestions of his own for 

 further improvement. 



2. On the Navicula used as a test by the Jurors of the 1862 

 Exhibition, which he thought was the " English " rhomboides 

 under the name of Xavicula affinis. 



3. " On a New Low-power Condenser : ' for use with objectives 

 as low as 4 in., the ordinary condenser not filling the field with 

 light when low powers were used. 



The way this difficulty may be surmounted is to construct 

 the condenser upon the telephoto principle. This has now been 

 done, and Messrs. Baker exhibited to the meeting a substage 

 condenser, made from Mr. Nelson's design, which has 4 in. of 

 focal length, and requires only 1 in. of working distance. With 

 this condenser the image of the flat of the flame bears the same 

 relation to a 4-in. objective with the large field of a P. and L. 

 No. 1, A eyepiece, as the image with one of the ordinary uni- 

 versal condensers with the top off does to a tw r o-thirds ; and 

 this is precisely what was wanted. 



