322 



well with all powers up to half-inch, but beyond that he found 

 he was in difficulties because of the want of flatness of field. 



The President inquired of Herr Leitz if he was doing any- 

 thing to help them in the way of making a long tube series of 

 lenses. Those which he had seen were all for short tube in- 

 struments, and he wanted to know if he could give them a little 

 more extension. He must not expect a very large sale, because 

 all students were now being taught that short tubes were the 

 correct thing. 



Mr. Ingpen asked if there were any difference between them 

 except in the matter of adjustment ; he understood from Pro- 

 fessor Abbe that there was no other difference. 



Herr Leitz said it was quite easy to make these objectives for 

 the long English tubes, and he would be glad to do so if he 

 found that there was a demand for them. There was no differ- 

 ence except in the adjustment. 



The thanks of the meeting were unanimously voted to Herr 

 Leitz for his communications. 



Mr. 0. L. Curties said he had brought for exhibition a speci- 

 men of Filaria, which had been sent from India. One drop of 

 blood contained about 300. 



The President reminded the members that in 1880 a very 

 valuable paper on the subject of Filaria3, by Dr. Manson, of 

 Amoy, was communicated to the Club by the late Dr. T. 

 Spencer Cobbold, which was published in the Journal (Ser. i., 

 vol. vi., p. 58, Plate xix.). 



Mr. Karop said that quite a new paper had, he believed, 

 lately been published by Dr. Manson on the subject, and which 

 probably contained many new observations on this remarkable 

 parasite. 



Mr. Bryce read a paper on a new Rotifer, Metopidia Farvula, 

 for which the thanks of the Club were returned. 



The following objects were exhibited : — 

 Nassula ornata, Ehr. ... 

 Ophrydium Eiclihornii 

 Filaria sanguinis hominis 



New microscope lamp 

 Amphipleura pellucida, 



Pantachromatic objectives ... 

 Notops hrachionus (mounted) ... 



