248 THE MICROSCOPIST. 



importance of this migration to the pathology of inflam- 

 mation. His experiment consisted in stretching the mes- 

 entery of a living frog, paralyzed by the subcutaneous in- 

 jection of I per cent, solution of curare, over a ring of cork, 

 and placing it under the microscope. The veins are seen to 

 dilate, and the colorless blood-corpuscles first cling to the 

 inner surface of the wall of the vessel, then a process from 

 the bioplast passes through the wall, which swells up out- 

 side, and in this w r ay a bridge is formed upon which the 

 whole substance of the cell creeps over. By their amoeboid 

 motions the cells wander further, and accumulate at the 

 irritated part of the tissue which becomes the point of de- 

 parture for future changes (Fig. 202). 



Strieker has shown, by experiments on the tongue and 

 cornea of the frog, that the migratory cells, or pus-cor- 

 puscles, in inflammation increase by division. 



Dr. Beale holds the opinion that although some of the 

 pus-corpuscles may be derived from the division of colorless 

 blood-cells, yet the great mass of them results from the 

 bioplasts of the tissues in which the pus-formation takes 

 place. In this he follows the earlier teaching of Virchow, 

 which supplanted the older view that pus-corpuscles origi- 

 nated in a structureless exudation. Dr. Beale recommends 

 the examination of a portion of cuticle raised by a small 

 blister, which may be stained with carmine, or examined 

 fresh in the serum of the blister. The bioplasm of the 

 inflamed epithelial cells will be found larger than in the 

 normal state, and in some instances will be seen to project 

 beyond the formed material of the cells, and the free 

 portions divide and subdivide in the exudation poured 

 out from the bloodvessels. 



In Chapter IX we have referred to Dr. Beale's views 

 respecting the elementary histological unit or cell, which 

 seem to agree with the phenomena recorded by Max 

 Schultze, Cohnheim, Strieker,* etc. So influential have 



* Strieker's Manual of Histology, chap. i. 



