322 DISEASES DUE TO HELMINTHS 



(2) Transfer to colourless cold tar creosote, allow to clear, and 

 examine in that fluid. 



After the examination is concluded pass through methylated spirit 

 back to 70 per cent, spirit as before to store. 



LARGE NEMATODES. 



These are treated in the same way as small ones except that they 

 cannot be cleared and mounted by the glycerine method. 



SMALL TREMATODES. 



Preservation. 



(i) Place alive in a test tube one-third full if i per cent, saline, and 

 shake vigorously. 



(2) Add to the test tube rapidly an equal quantity of saturated 

 solution of sublimate. 



(3) Shake vigorously for three minutes. 



(4) Transfer to 70 per cent, spirit to store. 



Examination without Mounting. 



As for small nematodes. 

 In order to make stained and mounted specimens : — 

 (i) Transfer from 70 per cent, spirit to a i per cent, solution of alum 

 to which is added a little ha^matoxylin, until the whole is a light claret 

 colour. The ha^malum solution (ha?matin, 2*5 grm., absolute alcohol 

 50 c.c, alum 50 grm. or to saturation, water 1,000 c.c.) diluted with 

 distilled water gives good results, and so does a weak solution of 

 carmine, but in that case longer staining is required. Leave in this 

 one to four days. 



(2) Decolorize slighllv with ^ per cent, acid water. 



(3) Wash well. 



(4) Dehydrate with spirit and oil of cloves. 



(5) Pass through zylol and mount in balsam. 



LARGE TREMATODES. 



Preservation. 



(i) Drop alive in a i per cent, saline and shake vigorously. 

 (2) Add formalin (commercial) to this to make about a 10 per cent, 

 solution, and shake vigorously until death occurs. 



The specimens can be kept in 10 per cent, formalin. 



Examination. 



This is best done by embedding and cutting sections. 

 To mount Specimens whole. 



(i) Press between two slides wliilst alive, and drop into 70 per 

 cent, spirit. 



(2) Stain and clear as in small specimens. 



