4io 



MODELS FROM SERIAL SECTIONS 



[Ch. XI 



Under the microscope the head will be at the left and the dorsal 

 side will appear toward the upper edge of the slide — away from the 

 observer. It will appear like the figure when the the book is turned 

 upside down. 



If the embryo is large it may be better to turn it around so that 

 the ventral side meets the edge of the section knife. If this is done 

 the sections will have to be cut apart and mounted one by one on the 



PiS 

 23 



Ss. 



Pig 

 Si 



6 

 23 



Sec _253 



10// 260 



1900 



Fig. 243. Slide of Serial Sagittal Sections Showing the Arrangement 



and Labeling. 



slide, otherwise they would be crosswise of the slide like the frontal 

 sections (fig. 240). 



§ 665. Labeling serial sections. — The label of a slide on which 

 serial sections are mounted should contain at least the following: 



The name of the embryo and the number of the series; the number 

 of the slide of that series; the thickness of the sections, and the num- 

 ber of the first and last section on the slide; the date. It is also a 

 convenience to have the information repeated in part on the left 

 end (fig. 237-243). 



Models From Seriax Sections 



§ 666. General considerations on modeling. — Anatomists have for 

 a long time produced models of gross anatomic specimens, and en- 

 larged models for minute details. 



Naturally, after serial sections of embryos and organs came to be 

 made with considerable accuracy and of known thickness, there was a 

 desire to make enlarged models which should be exact representations 

 of the original rather than the generalized approximations built up 

 as an artist produces a statue. 



