502 Observations on the Life-history of Leucocytes. 



as are here described, and that the observers were mistaken in supposing that the cells in 

 question were cancer cells. That a large congregation of leucocytes does occur in the 

 case of Jensen's graftable tumour renders this extremely probable, for we have seen that 

 among the leucocytes brought together by the introduction of a foreign body in the case 

 of Axolotl, some of them conjugated. Moreover, nothing in the nature of a conjugation 

 between cancer cells has been recorded by any other observers, although the alleged 

 fusion has been diligently sought for during several years. 



DESCRIPTION OF PLATE. 



Fig. 1. — Two leucocytes in Axolotl in which the nuclei are sending out protrusions. 



Fig. 2. — The two nuclear protrusions have joined, rings of chromatin masses have 



appeared at either end of the tube thus formed, and the chromatin is disappear- 

 ing from the lower of the two nuclei. 

 Fig. 3. — The nuclear membrane of the cell on the right is collapsing. The ring of 



chromatin masses has disappeared at the end of the tube nearest the nucleus 



that has absorbed the chromatin of the other. 

 Fig. 4. — Two leucocytes from the spleen of the guinea-pig, showing the nuclear protrusion 



from one attaching itself to the nucleus of the other. 

 Fig. 5. — A slightly later stage. 

 Figs. 6, 7, and 8. — Stages showing the absorption of the contents of one nucleus by the 



other. 

 Fig, 9. — Showing the complete collapse of the nuclear membrane of one leucocyte, with 



only a few shreds of the membrane remaining. 



