262 An Introduction to Medical Mycology 



the following technic: "A loopful of India ink is placed on a glass slide, 

 and a loopful of the culture material is quickly emulsified in it. A large 

 coverslip is quickly applied and pressed gently." Practice is necessary in 

 order to bring out the halo effect (in T. histolytica). Three precautions are 

 essential: the preparation must be made quickly; the drop of fluid must 

 be small; no previous mounting material, such as hydroxide, glycerin, al- 

 cohol or stain, may be present. 



4. BINDING AGENTS 



(a) Asphalt varnish.— This is a durable agent, which does not chip. 

 After a long period there may be some separation. Use while fresh. It may 

 be obtained from any biologic supply house. In New York City, Eimer and 

 Amend carry a satisfactory product. 



(b) Duco cement.— This is preferred by some. A seal is quickly attained. 

 There is a tendency to brittleness, and adherence may not be as reliable as 

 with other agents. 



(c) Clarite.— A newer product with which we have not had much ex- 

 perience. 



(d) Polyvinyl alcohol.— This may be mixed with phenol, lactic acid 

 and cotton blue. According to Huber and Caplin, it is said to clear and de- 

 hydrate as well as to provide a permanent hyaline mount. 



BIBLIOGRAPHY 



Henrici, A. T.: Molds, Yeasts and Actinomycetes (2d ed.; New York: John Wiley & Sons,. Inc., 



1947). 

 Huber, W. M., and Caplin, S. M.: Simple plastic mount for permanent preservation of fungi 



and small arthropods, Arch. Dermat. & Syph. 56:763, 1947. 

 Weidman, F. D., and Freeman, W. : India ink in microscopic study of veast cells, J. A. M. A. 



83:1163, 1924. 



