40 



Animal Micrology 



c) To avoid reversing sections in mounting, it is frequently 

 advantageous to have the imbedding mass trimmed unsymmetri- 

 cally. The edge which first comes in contact with the knife is 

 left longer than the opposite edge. One may thus readily dis- 

 cover when a section or part of a series has been turned over. 



11. Mount the object firmly in the microtome. It should just 

 clear the knife. The flat end-surface of the paraffin block should 



FIG. 29. Minot-Blake Microtome, designed especially for cutting thin sections. Manu- 

 factured by Buff & Buff Afj^tj Co., of Boston, Mass. 



be parallel to the edge of the knife, and the block so oriented 

 that in cutting, the long edge will meet the edge of the knife 

 squarely. 



12. Place the knife in position with the handle to the side 

 away from the wheel (if a rotary microtome is used). By means 

 of the adjusting screws tilt the cutting edge slightly toward the 

 object so that the side of the knife will not remain in contact with 



