TRANSACTIONS 



OF 



THE CROYDON MICROSCOPICAL AND 

 NATURAL HISTORY CLUB. 



1889-90. 



74. Some Hints on the Preparation of delicate Organisms 



FOR the Microscope. 



By Edward Lovbtt. 



(Bead Febraary 13th, 1889). 



Mr. Lovett said that such organisms as the ova of Mollusca, 

 Crustacea, Fishes, &c., -were often of such a nature as to be very 

 difficult of permanent preservation, but he had succeeded in 

 overcoming the difficulty satisfactorily by means of a fluid, the 

 density of which he modified in accordance with the organism 

 about to be mounted. This fluid was composed nominally as 

 follows :— 3 parts pure alcohol, 2 parts pure glycerme, and 1 

 part distilled water. This strength was suitable for young 

 crustaceans, the ova of the fishes, and for the tougher ova sacs 

 of the mollusca. For the ova of crustaceans and insects, and 

 for that of the very small fishes, one or two parts more of distilled 

 water might be added ; whilst for such exceedingly dehcate sub- 

 stances as the ova of the nudibranchiate Mollusca, zoophytes 

 extended from their capsules; and for various delicate fresh 

 water forms, a weaker formula than this was necessary ; but as 

 practice was the best instructor, he recommended his hearers to 

 be guided by what they found to be the best proportions. 



This fluid should be put into small glass tubes, with corks 

 bearing numbers corresponding to those in a note book, so that 

 full details of the contents might be recorded. These tubes 

 should be taken down to the shore by the collector, and the 

 organisms obtained should be placed therein alive, direct from 

 the sea. The length of time required for the preservation of the 

 object by the fluid varies according to the organism, from a week 

 to a year ; but some of Mr. Lovett's best preparations had been 

 soaking, before being mounted, for five or seven years ; and as a 



