lOl' PEOCEEDINGS OF THE SOCIETY. 



An Exhibition was then given, ilhistrating the use of polarized light 

 in inicrosco[>ical work. 



Mr. Scourfield said that in suggesthig this exhibition he had hoped 

 that they would not only have examples of the use of polarized light in the 

 study of rocks, minerals and other inorganic substances, but also a very 

 full demonstration of its value in connexion with organic structures. 

 Although the exhibition in this respect was by no means complete, he 

 thought that it did show very clearly that polarized light was a most 

 useful aid to research in the organic world. It might not always be 

 possible to find out absolutely new structures by its means, but it often 

 put one on the track of things that would otherwise be overlooked, or 

 gave a new significance to well-known details. He thought that work 

 with high powers and a very strong light in conjunction with the polari- 

 scope would probably open up a very fruitful line of research. For 

 instance, in examining Volvox in this way he had noticed that the red 

 eye-spots of the individual green cells show out like so many little glow- 

 lamps, probably indicating a very definite specialized structure in 

 addition to the pigment. Tlie eye-spots in other forms of the Volvoeacese, 

 such as (Jhlaniydomonas, he found to behave in the same way. In many 

 Desmids strong polarized light with high magnification revealed myriads 

 of bright granules often arranged in characteristic ways. In a species 

 of Pleurotsenium he had seen the cell sap charged with minute scintil- 

 lating particles, not uniformly distributed, but massed at different spots, 

 in one case ending abruptly about half way along a semi-cell as if 

 retained by a septum. It was just possible that this was a very early 

 indication of approaching cell division not recognizable at that stage in 

 any other way. 



Mr. Scourfield also read extracts from letters he had received from 

 Mr. Ashe and ^Ir. Wycherley, who were unfortunately unable to be 

 present, giving many examples of the way in which they had found the 

 use of polarized light helpful in their work, especially in the examination 

 of foodstuffs, drugs, fibres used in paper manufacture, etc. 



Exhibits were made by 



F. Addey , . . Transverse section of leaf of Eahm, 



showing columnar sclerides. 



M. A. Ainslie . . Eesolution of fine Diatom structure, 



Nitzscliia singalensis, 117,000 trans- 

 verse striae per inch ; practically 

 unresolvable in styrax without polar- 

 ized light. 



S. G. Akehurst . . Wing case of Beetle, Dichirotrkhus 



pubescens, showing rows of tiny 

 medallions with characteristic black 

 cross. 



W. E. Watson Baker . A'arious rock and mineral sections, 



chemical substances, etc. 



F. E. Cocks . . Meh'reria rinijens. 



E. Cuzner . . . (voumarin, Platino-cyanide of Yttrium. 



