3i8 



SERIAL SECTIONING 



[CH.X 



Or with such an organ as the liver, the skin, etc. , the sections 

 may be parallel with the surface, (Surface Sections) or at right 

 angles to the surface ( Vertical Sections) . 



ORDER OF THE SECTIONS IN A SERIES 



§ 473. Order of Serial Sections. — Some plan must be 

 adopted in arranging the series or only confusion will result. An 

 excellent plan is to arrange the short pieces of ribbons for a given 

 slide as the words on a page are arranged. That is, section No. 1 

 is at the upper left hand corner. The next row of sections begins 

 where the first row left off, etc., (Fig. 253). 



As the paraffin stretches considerably one must cut the ribbons 

 into pieces considerably shorter than the cover-glass to be used. 



Fig. 253. Slide of an embryologic series showing the method of arranging 

 a sagittal series. This is the 15th slide of the series. The sections are ar- 

 ranged like the words and lines in a book, i. e., from left to right. {From 

 ' ' Guide to Histology and Embryology in Cornell University. ' ' ) 



Both the paraffin and collodion methods are adapted to the 

 preparation of series. The paraffin ribbons are easier to manage 

 and easier to make than the serial sections in collodion. 



By arranging the collodion sections as they are cut on the knife 

 in collodion sectioning (§ 457), one can put them on the slide in 

 perfect series by the tissue paper method (§ 458). 



If the sections are large, as in cutting serial sections of the cen- 

 tral nervous system, the series can be kept in order in a small dish 

 by putting a piece of tissue paper over each section and piling them 

 up. If the vessel is small enough the papers and sections will not 

 shift and get out of order. Or one might put a single section in a 

 Syracuse watch glass and pile them up in series (Fig. 208). Then 

 in mounting the sectious can be taken in order. 



