JOURNAL 



OF THE 



ROYAL MICROSCOPICAL SOCIETY 



FEBRUARY 1900. 



TRANSACTIONS OF THE SOCIETY. 



J. — On the Preparation of Marine Worms as Microscopical Objects. 

 By H. C. Sokby, LL.D., F.K.S. 



{Read 15th November, 1899.) 



AccoRDiNa to Pliny, animals were sometimes preserved in honey. 

 For example, he says he saw a young centaur so kept, which had 

 been born in Thessaly ; and that honey is of such a nature as will 

 prevent putrefaction. It therefore seemed to me desirable to try 

 whether a strong solution of cane-sugar would be useful, in order to 

 dissolve out the salt from marine animals which I wished to dry on 

 glass and mount in Canada balsam. After remaining a short time 

 in the syrup, they were treated with water, to remove the greater 

 part of the sugar. The results were to some extent satisfactory ; 

 but it appeared to me probable that bad effects might follow from 

 the subsequent crystallisation of the sugar. It therefore occurred to 

 me that a moderately strong solution of glycerin might answer 

 equally well in removing salt, and could not subsequently crystallise. 



1 very soon found that, in thus treating a species of Nereis worm, 

 very common in some of the Essex estuaries, it was possible to dry 

 small specimens and mount them in balsam, without decomposition 

 obliterating the minute blood-vessels. After trying various modifica- 

 tions of the process, I at length found that good results could be 

 obtained by adopting the following method. I took specimens only 



2 or 3 in. long, because the structure is confused when they are 

 too thick. These were put direct from the sea- water into strong 

 glycerin diluted with an equal volume of water. In this they quickly 

 died, and after remaining in it for about 10 minutes, were seen to be 

 considerably reduced in size by the transfusion of water into the gly- 

 cerin. They were then transferred to water, and kept in it for about 

 ten minutes, so as to remove most of the glycerin, and to cause them 

 to expand to about their original size. They were then quite limp, 

 and could easily be arranged on microscope-slide glasses, and were 

 dried as quickly as they could at the usual temperature in the open 

 air, and in doing so became thin, but shrank very little laterally. Some 



Feb. 21st, 1900 B 



