OF DENISON UNIVERSITY. 7 



purpose, should contain some dryer, such as turpentine or Japan dryer 

 because the wax but poorly absorbs the oil. 



Labeling. Labeling the different parts, adds greatly to the future 

 value of the model. Any good mucilage answers the purpose of an 

 adhesive, and is preferable to glue. 



Modeling Instrutnents. Modeling instruments may be had from 

 any biological supply house. However, those most necessary may be 

 improvised without much trouble. 



One of the most useful modeling tools is made by fitting a small 

 spoon into a wooden handle. With this simple instrument almost the 

 entire process of modeling may be carried out. 



Another convenient tool is an ordinary long bladed knife. For 

 rounding out concavities, a small iron bar with a spherical enlargement 

 at one end, and fitted Avith a wooden handle, is a useful accessory. 



Card-Board Modelling from Microscopic Sections. This method is 

 a modification of the former. But serves to represent, in addition to 

 form and relation of parts, the histological elements which enter into the 

 tissues. 



The process is essentially the same as that for wax modeling, ex- 

 cept that the sectional patterns are traced on card-board instead of wax, 

 and mounted on wires in a frame, instead of being fitted and cemented 

 together. 



After the sections have been cut out, the minute histological struc- 

 tures are sketched on each one, from a microscopical examination of 

 the corresponding sections in the series. 



Two or more wires are stretched within a light frame-work, in such 

 a manner that the model is suspended in the required position. In 

 each of the card-board sections, are two or more slots, through which 

 the wires are to pass, when the sections are in position. The sections 

 are separated from each other by small beads which are strung on the 

 wire for that purpose. 



By such an arrangement any section may be taken out of the 

 model and its histological structure readily seen. 



