Parker.—On preserving Cartilayinous Skeletons. 259 
about to be described enough to make me feel tolerably confident in recom- 
mending it as of special value in the case of cartilaginous skeletons, and 
useful for hollow viscera, the exoskeletons of Crustacea and Echinoder- 
mata, etc. 
It will be advisable to describe separately the chief applications of the 
method. 
1. Cartilaginous skeletons. I find the best way to clean the skeletons of 
fresh Elasmobranchs is to clear away the flesh, etc., very roughly, after 
removal of the skin and viscera, then to dissect away the gill-arches, and 
then to plunge the body into boiling water for a few seconds. This softens 
the muscle and connective tissues so much that their removal is rendered 
quite easy, while, if prepared in the cold, it is almost impossible to remove 
the tough perichondrium without injury to the cartilage. In the case of even 
moderate sized specimens it is often necessary after separating the skull, 
vertebral column, and fins, to dip each part again into boiling water. With 
very large specimens it is necessary to separate the different regions of the 
skeleton, and even to cut the vertebral column into segments before plunging 
them in the water, as otherwise no ordinary vessel will suffice for their 
immersion. In the case of spirit specimens parboiling is not necessary. 
The gill-arches should be thoroughly hardened in spirits and then cleaned 
by ordinary dissection; even a slight application of heat causes the 
separation of their delicate cartilages. In the same way no heat must be 
employed in the preparation of persistent notochords, as for instance in the 
case of Callorhynchus. 
When thoroughly cleaned, fresh specimens should be placed in strong 
methylated spirit for two or three weeks. This hardens the cartilage and 
produces a certain amount of shrinking. In the ease of large skeletons 
(sharks, etc.), this operation may be dispensed with on economical enande, 
but without it the results are never so satisfactory. 
When thoroughly hardened the specimen is transferred to one of the 
following fluids -— 
Guycrrrve Fium, A. Guxcenine From, B. 
Glycerine .. ae a litre, Glycerine .. oe -. IL litre. 
Water oy ae Pe be ie Ze W: ma ae 1 * 
Corrosive sublimate ae grams. Concentrated solution of 
Alum ve is i, ie Phenol .. we ae keel 
Alum 
Of the two fiuids, Ey satan to sive the teak sculls; Ou ae aete. oF 
Specimens being better than that of pen eo mre eee 
. oe hardened 
| the sooo Ay as consive ane a n metals, 
~ 
