PRESERVATION OF INVERTEBRATA. 21 
ON THE PRESERVATION OF INVERTEBRATA. 
ee 
BY PROF. 1. JEFFERY- PARKER, 
—————— 
With the exception of those Invertebrata which can be satis- 
factorily preserved in the dry state—notably insects—the only 
thoroughly good permanent preservative is alcohol—the only 
one, that is, which preserves both internal and external structures 
with the minimum amount of alteration. I have italicized the 
word “permanent” in the foregoing sentence, because it is often 
of advantage to place a given specimen in alcohol only after 
previous treatment with some other preservative. Into alcohol, 
however, it should be sooner or later placed, and there retained ; 
and it is important to remember that the alcohol should be 
strong—undiluted rectified or methylated spirit. Anyone 
making a collection of hydrozoa, worms, molluscs, &c., must 
therefore be prepared for a considerable expenditure of 
alcohol, undue economy in this respect always resulting in flabby, 
half-rotten specimens, and complete waste of time and trouble. 
Besides alcohol, the following are the chief requisites :— 
1. Picric acid, used in the form of a cold saturated solution. 
2. Chromic acid, used as a 0.5 per cent. solution. 
3. Potassium bichromate, a 1 per cent. solution. 
4. Osmic acid, a I per cent. solution. (This must be kept ina 
dark place. It is advisable to cover the bottle containing it with 
black paint or paper.) 
Be reetic acid. 
6. Corrosive sublimate. 
7. Glycerine. 
8. A number of bottles of various sizes. Wide-mouthed bottles 
are, in nearly all cases, the best—z.g , the ‘‘ Preston Salts” bottles 
sold by druggists, pickle bottles, &c. A few ointment pots—small, 
shallow porcelain vessels with lids, are also useful. 
g. A ‘lifter,’ for transferring small and delicate organisms, 
which cannot be touched with the fingers, from one vessel to 
another. A very convenient form is made by flattening out about 
three-quarters of an inch of the end of a piece of stout copver 
wire, and then bending the flattened portion upon the remainder, 
at an angle of about 100° to 120°. 
In collecting marine invertebrata, it is advisable to take 
vessels of different sizes; for instance, a common tin “billy” 
for large objects, and a few  well-corked wide-mouthed 
bottles for small organisms. It is a good plan to take at least 
one bottle full of picric acid or potassium bichromate solution, 
and to place therein immediately any particularly delicate 
