262 



Mr. T. C. White said that the paper was certainly very exhaustive, and 

 "would form a valuable and important addition to the literature of the Club. 

 He should like to ask Mr. Groves if he could give any directions for the use 

 of osmic acid as a preservative fluid for Polyzoa. He had tried it, but 

 found that it acted too powerfully upon them, and caused distortion. 



Dr. Matthews said he did not hear any notice of the process of staining 

 by perchloride of iron followed up by pyro-gallic acid, as described by Dr. 

 Hogg an. 



Mr. Death wished to ask whether the staining fluids were not divided 

 into two classes, one of which acted by reduction, also whether at any time 

 Mr. Groves had any difficulty with the alcohol. It had been stated that the 

 fresher the subject the better, and in cases where they used fluids with 

 a reducing action, was this true ? Did Mr. Groves find that he need not 

 change the fluid so often if he stirred it up ? — did not frequent stirring 

 enable the fluid to be used longer ? — and in using salts of gold did he use 

 an acid solution ? He fully concurred with Mr. White as to the value of 

 the paper. 



The Chairman said that he had noticed that glycerine was very frequently 

 suggested as a good medium, also acetate of potash, but he might suggest 

 that their old friend, Canada balsam, was also very useful. With regard 

 to silver stained specimens, he found that they kept their colour exceed- 

 ingly well, and he had some which had done so for 10 years. In the matter 

 of gold, however, he had generally found that they deepened in colour in a 

 most objectionable way, and he should be glad to know how this could be 

 prevented. Osmic acid did very well also in balsam. 



Mr. Groves, in reply, said he had no experience in mounting Polyzoa. 

 He had not tried Dr. Hoggan's process, and knew nothing about it. He 

 had tried stirring up the fluid, and thought it enabled it to be used longer. 

 Salts of gold solution was neutral. He found nitrate of silver specimens 

 keep very well. Osmic acid specimens he had never put up in balsam. 



The Chairman gave notice that nominations for Officers and Committee for 

 the ensuing year would be made at the next ordinary meeting. Announce- 

 ments of excursions and engagements for the ensuing month were then 

 made, including that of the Excursionists' annual dinner for June 19th, 



After the meeting the following objects were exhibited : — 



Section of Oriental fig, double stained ... Mr. F. W. Andrew. 

 Doli chopus trivialis, mounted so as to pre-") m * T C f 



serve the iridescence ... ... j 



Zygnenia quininum, in various stages of) Mr H G Glasspoole. 



conjugation ... ... ... ... ) 



Human skin X 170, stained in the mass") ,, T w ^ 



'> Mr. J. W. Groves. 



with borax and carmine ... ... J 



Tooth of Shark Mr. J. J. Hunter. 



Sertularia cupressina, coated with Diato- ) -,r . v, ,r. , , 

 mncece ... ... ... ... J 



