416 Notes. 



then burst, leaving the pigment in the centre of the leucocyte 

 (fig. 6), at 3.14 p.m., and a new vacuole started to form around it 

 again. 



During all this time the leucocyte was constantly undergoing 

 amoeboid movements, and at 3 . 22 p.m. the vacuole with its pigment 

 lay at one end (fig. 8), and it looked as though it would be dis- 

 gorged. But it was not so, and, despite this amoeboid activity, the 

 pigment — surrounded by a vacuole which grew, burst, and re- 

 formed repeatedly — remained within the leucocyte, sometimes at 

 the centre, sometimes at the periphery. 



For the first hour there was only one leucocyte in the field, but 

 then a second corpuscle appeared at the edge and moved towards 

 the centre, and by 3.30 p.m. (fig. 9) had approached and apposed 

 itself to the first corpuscle. Around the circumference of this it 

 proceded to travel (figs. 10-12), and at 3 . 49 p.m. it had wandered off 

 again, and numerous red blood corpuscles separated the two (fig. 13). 

 No further change could be observed during this apposition. 

 This second leucocyte (a?) remained in the field, at times approach- 

 ing the first one, and some time later a third leucocyte appeared (y), 

 which was followed by two more, making altogether five under 

 observation at one time (figs. 14-19). At 4.33 p.m. leucocytes x 

 and y had apposed themselves to the edge of the original phagocyte 

 (fig. 20) and withdrew a short distance. Meanwhile another was 

 approaching (fig. 21), and this formed with the first two reinforce- 

 ments a group of three, which at 4 . 38 p.m! completely surrounded 

 the pigment-containing leucocyte (fig. 22), which at this time con- 

 tained several small vacuoles, each enclosing some pigment. At 

 4.40 p.m. they had all separated again (fig. 23) and one of the re- 

 inforcing corpuscles now contained a small particle of pigment 

 surrounded by a vacuole, and with this it wandered off, making 

 unsuccessful attempts to leave the pigment behind at the end of a 

 pseudopodium (fig. 24). This reinforcing process was repeated 

 several times, and at 5.16 p.m., and later, pigment was noticed in 

 several of the leucocytes that had entered the arena entirely free 

 from pigment — hence it could not have been derived from other 

 crescents caught by themselves (fig. 26). 



By this time the activity of the corpuscles was diminishing, but 

 that they were still alive was shown by the apposition of two at 

 6.5 p.m. (fig. 27), no others being seen in the field, whilst at 



EXPLANATION OF PLATE XVI. 



Only the first leucocyte is stippled, the others merely outlined. The nucleus 

 has been purposely omitted in most of the figs, to simplify the description. In 

 figs. 13-18 red corpuscles are shown, but drawn too small. In fig. 29 the bilobed 

 deep staining nucleus is shown. The arrows indicate the direction in which the 

 corpuscles were moving at the time of drawing. 



