DISARTICULATING SKULLS. 109 



position and fastened with pins or strings and allowed to dry. The 

 swollen ligaments will shrink very greatly, so that what might have 

 seemed a very imperfect preparation when moist will be excellent 

 when dry. When the specimen is dry, rough projections of liga- 

 ment may be removed with a sharp knife. 



Flexible Natural Skeletons. If it is desired to have the lig- 

 aments flexible, the preparation may be soaked after it is partly 

 dry for from 16 to 12 hours in either Wickerscheimer's fluid ( 299), 

 or a mixture of a saturated aqueous solution of arseniate of soda, 4 

 parts, and glycerine 1 part. 



253. Preparation of the Bones of Young Animals. The 



liquid soap process is to be preferred. But during the boiling the 

 bones must be carefully watched, and the boiling should be carried 

 little farther than for making natural skeletons. The epiphyses 

 must not be allowed to separate from the diaphyses. 



The skulls of new born kittens may be nicely prepared in this 

 way, and the sutures show with great distinctness. 



254. Disarticulating Skulls. Choose a young or barely 

 mature animal for this preparation, since the cranial sutures are 

 liable to be obliterated in adults. 



Prepare the skull by the liquid soap process ( 248). Continue 



the final boiling for half an hour longer than for a skull that is 



not to be disarticulated. While still moist, the bones may be 



separated by steady traction. This may be done with the greatest 



.ease if half grown animals are used. 



Skulls that have become dry may be boiled for half an hour in 

 the liquid soap to soften the gelatinized connective tissue binding 

 them together. 



Macerated young skulls may be disarticulated by carefully 

 pulling and prying the bones apart. 



An excellent plan is to fully disarticulate one side of a skull, and to leave the other 

 with the bones in situ. 



Disarticulation of Large STculls. If a large skull is prepared 

 by the liquid soap process it should be thoroughly softened by 

 soaking in water two or three days or by boiling an hour. Then 

 fill the cranial cavity with dry beans or peas, force a cork tightly 

 into the foramen magnum (Fig. 57) and place the skull in water. 

 The swelling of the peas will force the bones apart. Macerated 



