JV/iole Mounts 381 



creosote (or aniline or plienol) (prevents them from becoming 

 brittle), 2 changes. It opaque patches persist, return them to abso- 

 lute alcohol. 



4. Impregnating with moinitant can be difficult. Specimen may 

 collapse and turn black or opaque when taken directly from 

 alcohol or clearer to moinitant. Impregnate gradually by adding 

 each day a drop or two of mountant to the clearer containing the 

 specimen. Carefully stir the mountant into the solution. 

 Galigher [1934) uses a cone of filter paper containing the moun- 

 tant, and allows it to enter the solution gradually and continu- 

 ously. 



When the clearer has obviously thickened, allow concentration to 

 continue by evaporation. 



5. Mounting sometimes requires considerable experience (and pa- 

 tience) in judging the correct method and amount of moinitant. 

 Some specimens, large or delicate, should have supports under the 

 cover glass, in the former case to prevent tilting of the cover glass, 

 in the latter to lessen chances of smashed specimens. Various 

 materials may be used to support the cover glass; bits of cover 

 glass or slide, thin glass rods, circles, squares, or strips stamped or 

 cut out of heavy aluminum foil, bits of glass wool. 



Place a drop of mountant on slide and place specimen in it. 

 Lower cover glass carefully; keep it flat (not tilted); have specimen 

 in center of mount. If several specimens are to be mounted under 

 one cover glass, chance of their slipping out of place is lessened by 

 allowing the mountant to air dry for a few hours. Place a bit more 

 mountant over them and add cover glass. Warming the cover glass 

 aids in bubble prevention. 



comments: 



Demke {1952) embeds helminths in celloidin to support them. De- 

 hydrate through absolute alcohol, alcohol-ether and into thin cel- 

 loidin. Pour celloidin and specimens into flat dish (petri dish); allow 

 solvent to evaporate slowly. Cut out squares of celloidin containing 

 specimens, dehydrate, clear and mount. No other support of cover 

 glass required. 



Rubin [1951) uses PVA mounting medium, page 120. See other 

 mounting media in that section. 



Glycerol Jelly Mounts 



Many materials, including frozen sections, may be mounted directly 

 from water into glycerol jelly. If there is danger of an object collapsing, 



