1892.] On the Wandering (Migrating) Cells of the Frog. 271 





///. The cells of the mass commence to regain their indi- 

 viduality and slowly separate. The separation is in two very dis- 

 tinct stages, and when the individual cells are again to be seen the 

 mass is found to consist of a central giant 1 hyaline plasmodium, 

 formed by the very complete fusion of the four hyaline cells, and 

 enclosed by a crust of eosinophile cells. The -first stage in the disso- 

 lution of the mass is the separation and wandering away of the 

 eosinophile cells, fully charged with the second set of spherules, 

 which have now become truly eosinophile. A very curious appear- 

 ance is presented as they shred themselves off the central hyaline 

 mass. This plasmodium or giant cell is now seen to be an amoeboid 

 body, with several food vacuoles containing ingesta in the form of 

 the remnants of the chain of bucilli. It pushes out on one side 

 long filiform pseudopodia, which resemble those of the Heliozoa in 

 their sluggish, streaming movenaen't&, .while from the other side pro- 

 ject short round pseudopodia. 



The hanging drop- contains, at this stage, multitudes of these 

 phagocytic plasmodia, with free eosinophile cells and free hyaline 

 and rose- staining cells. 



Stage IV. This is the second stage of the disintegration of the 

 cell masses. The food 'vacuoles of the plasmodium close up, and the 

 whole structure becomes lobed, taking on the appearance of a heap 

 of hyaline cells, which- subsequently separate into the original four 

 cells. 



While these stages are in progress the rose-colouring cells are 

 increasing in size and number. They are at first small and spherical, 

 with not very abundant cell substance. Later they become large, 

 angular, and sometimes vacuolate, and their cell substance becomes 

 completely filled with basophile, rose-staining granules. 



The activities of the rose-staining cells are, we believe, directed 

 towards the removal of foreign noxious substance in solution in the 

 plasma. We find that if the bacterial poisons accumulate beyond a 

 certain point they paralyse the eosinophile cells, and destroy the 

 hyaline cells. This is- prevented, in part afc any rate, by the action 

 of the rose-staining cells. We correlate the increase in the granula- 

 tion of these cells, or, in other words, the increase in the amount of 

 rose-staining substance, with the removal of the bacterial products. 



The conflict thus consists of, first, the maiming of the bacilli by the 

 eosinophile cells ; secondly, the removal of the remains of the bacilli 

 by means of the ingestive and digestive activity of the hyaline cells ; 

 and, thirdly, the removal of dissolved foreign substances by the rose- 

 staining cells. We do not propose to deal at present with the further 

 processes of repair. 



