94 The American Naturalist. [January, 
Among the undesirable effects may be mentioned : 
1. Swelling of tissue from absorption of water. 
2. Partial solution of connective tissue elements. 
3. Diminished elasticity, sometimes brittleness, of glands, ducts, and 
membranous viscera so that they may not survive the rough usage of 
the average beginner. 
4. The action on tissues rich in proteids as muscles of the terrestrial 
vertebrates is something like dissociation. The connective tissue is 
either softened or dissolved so that the fasciculi and fibres are easily 
teased apart. 
5. Muscles are shortened so that the limbs are usually flexed. Ifthe 
limb is forcibly extended, either the muscles themselves or the tendons 
break. The dissection of individual muscles is liable to tear them. If 
the specimen has been in the fluid for several months, the muscles be- 
come rigid and brittle. If the limb be forcibly adducted, the hume- 
rus or femur will usually break. The separation of individual muscles. 
and the demonstration of their actions are very difficult or even im- 
possible. 
In June, 1895, a lot of sea-lampreys were prepared by injecting 2 
per cent. formal through the dorsal aorta. They were then put into 
2 per cent. formal. The solution was changed three times and about 
Sept. 1, they were put into 50 per cent. alcohol. In Jan., 1896, the 
specimens had shrunken slightly. Preservation was fair, with the 
exception of a long longitudinal check in the axon (notochord) and 
the blood vessels did not show so well as in the previous year when al- 
cohol was used for injection and preservation. 
Brains.—Formal appears to be almost an ideal fixer and preserva- 
tive for brains where gross morphology is the object. They are tough 
and flexible; the alba, cinerea, and fibre tracts are well differentiated. 
The natural color is more perfectly retained than where other agents 
are employed. But membranous portions, telas, and plexuses are not 
so well preserved as where alcohol is used 
The following mixture was sa aladoniiy employed for sheep brains— 
a 2 per cent. solution of forma 
Formal (40 per cent. solution) ; wit 120-00 
Aea chloride... i . 46 grams. 
Wate 
After 5-8 inhi sles nostima may on into 2.5 per cent. formal in- 
definitely. 
Eyes.—Sheeps’ eyes were well preserved in 2 per cent. formal; the 
cornea, lens, and vitreum had a more natural appearance but the lens, 
