APPENDIX: 



INCLUDING THE MOST USEFUL HISTOLOGICAL 

 METHODS. 



THE advances made during the last few years in the preparation 

 of tissues for microscopical examination have been so important, that 

 no one proposing to undertake practical histological investigations, 

 normal or pathological, can afford to ignore methods of work which, 

 although somewhat exacting, yield results far superior to the older 

 processes. With the increased facilities for producing thoroughly 

 good and accurate preparations the current standard of excellence 

 has advanced, and results formerly viewed with complacency are now 

 often regarded as incomplete and correspondingly unsatisfactory. 



The activity of the last half-dozen years has resulted in greatly 

 multiplying the details of histological technology, since each worker 

 determines what new procedures or modifications of existing methods 

 are advantageous for his own special purposes. Useful, and for the 

 advanced worker indispensable, summaries of the ever-increasing 

 methods of microscopical investigation are to be found in the volumes 

 especially devoted to technology ; of such works in English the excel- 

 lent " Microtomist's Vade-Mecum," by Bolles Lee, may be recom- 

 mended, supplemented by the notices of new methods presented in 

 the current issues of the Journal of the Royal Microscopical Society. 



In the present place, however, no attempt will be made to discuss 

 even incompletely many of the methods finding use at the hands of 

 various investigators ; but, on the contrary, only a few processes will 

 be described which extended use has proved to be thoroughly trust- 

 worthy and satisfactory. The student undertaking such work for the 

 first time is strongly advised to persevere with the paraffin method, 

 as here described, since, when properly employed, it may always be 

 depended upon to yield the most gratifying results. Failures, sure 

 to beset the beginner, should be carefully analyzed and be made to 

 yield the experience which will guard against their repetition. 



The manipulations necessary for the conversion of the fresh tissue 

 into the finished preparation are : 



1. Fixation of the tissue. 



2. Preservation of the fixed tissue. 



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