1892.] THE MICEOSCOPE. 181 



Benzol or chloroform balsam. Glycerine and Farrant's solution 

 are all used cold, and may be had at the dealers'. 



56. Where may IJind a reliable description of the di^erences 

 between an animal and vegetable cell? 



vSee Carpenter on The Microscope, 7th edition, page 461. 



57. What is the best method for tnakiiig per7Jiane7it mounts 

 of urinary crystals'? 



Form the crystals on the slip, dry them and mount in balsam. 



58. Hozv may earth worms be preserved for sectioiiing? 

 Keep the worms in a vessel containing wet blotting-paper, for 



several days, to clean out the intestine ; pin them on a slip of wood 

 to keep them stretched ; place them into alcohol to harden. Keep 

 them in strong alcohol until they are cut. 



59. What is the method for grinding sectio?is of teeth? 

 What apparatus is needed? 



Cut the tooth into thin slices with a fine saw ; rub one of the 

 sections on a scotch-stone with the end of the finger, using water ; 

 with care, good sections can be made without other apparatus. 

 The pressure of the finger can be regulated to bear lightly on a 

 thin corner or heavily on a thick edge. Very large teeth should 

 be cemented on a glass slip and ground in the same way. See 

 Microscopy for Amateurs, by T. Charters White. 



60. What is the di^erence ??iicroscopically between Colum- 

 nar Epitheleo7na^ Adeno7na and Papillo7na? 



In brief, to keep within the limits of this column. Columnar 

 eptiheleoma is soft, the margins infiltrate the surrounding tissues ; 

 the tubes are fibrillated connective tissue, lined with columnar 

 epitheleum, not intimately attached ; large blood vessels in the 

 stroma between the tubes. Adenoma is soft, usually encapsulated ; 

 the glandular tissue abnormal, not of the type of the matrix ; 

 tubes usually obstructed with cells and irregularly disposed ; blood 

 vessels not numerous but are in the tube walls. Papilloma is 

 hard, not infiltrating ; is an overdevelopment of the normal 

 papillae of the part ; being inflammatory is very vascular and con- 

 tains numbers of leucocytes. These latter may simulate infiltra- 

 tion. In cancerous forms of papilloma the large multi-nuclear 

 cells may be seen in alveoli. 



61. What is the best 7nediu77i for mounting pish parasites? 

 Soak them in alcohol, glycerine, and water, equal parts of each, 



and mount in Farrant's solution, or glvcerine. 



62. How shall I 77ioti7it fsh eggs to show structure^ also 

 e77ibryo fsh? They are nozu in glycerine. 



These are rather opaque objects and are best mounted in balsam, 

 but few detailsof structure will be seen, however. Special prepara- 

 tion and teasing are necessary. 



