143 



ous system, of an entire eye, or tissues or organs con- 

 taining much fibrous tissue. It may be used whenever not 

 very thin sections (less than 10,"-. to 15;;-.) are required. 

 The celloidin or collodium need not be removed before 

 staining or mounting ; and unless the aniline dyes are used 

 for coloring, very little stain is taken by the celloidin. The 

 sections need to be cleared in oil of bergamot, as the oil of 

 cloves dissolves the celloidin. The following method for 

 staining and mounting celloidin sections in series, is recom- 

 mended by Weigert : * 



(1) A clean glass plate is covered with a thin layer of 

 a solution of collodium ; this is to be spread out as evenly 

 as possible over the entire surface. The plate is now 

 placed on edge, and the collodium allowed to dry, care 

 being taken to keep the dust from it. 



(2) A section is placed on a strip of "closet paper," 

 near one end. . Succeeding sections, as soon as cut, are 

 placed to the right of it. They are removed from the 

 knife to the strip of paper, by holding the paper extended 

 under the knife, and slipping the section onto it. To keep 

 the sections from drying, the strip of paper is, after the 

 removal of every section, placed in a flat dish, in which 

 several layers of filter paper, have been spread out and 

 thoroughly saturated with 80% alcohol. On each strip of 

 paper is arranged only one row of sections ; the strips are 

 kept in the dish in the order used. 



(3) As soon as a number of strips have been covered 

 with sections, they are arranged, sections downward, on 

 the layer of collodium above described, and gently pressed 

 to it. The strips of the papei can now be removed, the 

 sections adhering to the layer of collodium. Several layers 

 of filter paper are now pressed over the sections, in this 

 way removing as much of the alcohol as possible. 



(4) Before the sections have time to dry a layer of 

 the collodium solution is poured over them, equally dis- 

 tributed, and allowed to dry. As soon as dry the plate 

 may be placed into 80% alcohol, where it may be kept, or 



* Taken from Rawitz Leitfaden der histologischen Uutersuch- 

 ungen. Page 37. 



