482 



PROCEEDINGS OF THE SOCIETY. 



MEETING 



Held on the 15th of June, 1904, at 20 Hanover Square, W. 

 Dr. D. H. Scott, F.R.S., etc., President, in the Chair. 



The Minutes of the Meeting of the 18th of May, 1004, were 

 read and confirmed, and were signed by the President. 



The List of Donations to the Society, exclusive of exchanges and 

 reprints received since the last Meeting, was read : 



From 

 Two Slides of Diatoms, mounted by E. Thum in realgar, on \ -tr n t t% *• 

 flint glass Blips, the covers being also of flint glass .. .. ) Mr ' L - Lees Lurt,et - 



The Secretary said the Society was much indebted to Mr. dirties 

 for the two test slides mounted in realgar. They would replace a pair 

 of similarly mounted slides which had so deteriorated owing to the 

 decomposition of the mounting medium that they were now useless. 



The thanks of the Society were voted to Mr. dirties for his donation. 



Mr. Thos. Powell exhibited a ? V: ln - apochromatic homogeneous 

 immersion objective of his own make, which he thought might be of 

 some interest as it was not likely that he would be able to make many 

 more. 



Prof. Hartog' exhibited, under the Microscope, a slide prepared and 

 lent to him by Prof. Vejdovsky, which showed with remarkable distinct- 

 ness the first segmentation spindle and centrospheres in the embryo of 

 Rhynchelmis, a somewhat rare species of leech. This was so large that 

 it could be seen with a pocket lens and was very distinctly shown under 

 a £-in. objective with a B eye-piece — usually much higher powers were 

 required to see these things. The slides showed that with all the wealth 

 of detail which appeared in the very beautiful drawings made by Prof. 

 Vejdovsky * nothing had been added which could not be seen in the 

 specimens, and that these drawings were faithful representations. It was 

 interesting to notice the remarkable resemblance between this develop- 

 ment and what was seen in the field of force between two unlike magnetic 



* See Vejdovsky and Mrazek, " Umbildung des Cytoplasma walirend der Befruch- 

 tung und Zellteilung," Nach den Untersuckungen am Rhynchelmis Eie. : Archiv. 

 Mikr. Anat., lxii. (1903) pp. 431-579. 



