134 MYCETOZOA. 



the prize, half of it would sometimes be sucked in by one 

 of the competitors, then the other would have the advantage, 

 at length one of them released its grasp and the bacillus was 

 engulfed by the conqueror. When a swarm-cell crawls along 

 a glass slide it extends itself in a linear form with the cilium 

 extended, with a movement reminding one of a creeping snail, a 

 motion so remarkable that I have often gazed at it with astonish- 

 ment ; I was once watching a swarm-cell moving in the manner 

 described, when in its journey it came upon a little group of bacilli 

 lying on the glass slide ; the vibrating tip of the otherwise rigid 

 cilium appeared to detect their nature on coming in contact with 

 them, for the creature spread itself in an anoeboid form over the 

 group and remained in this position for a minute and a-half ; it then 

 again extended the cilium and crept away in the linear form. I 

 now saw that three of the bacilli had been taken away and were 

 enclosed in a vacuole in the body of the swarm-cell. After 

 continuing the crawling movement for some time the creature came 

 to a stand, and, raising the cilium from its horizontal position, gave 

 a few lashing strokes, assumed the pear-shaped form, and swam 

 away to join its dancing companions. It is not only the swarm- 

 cells that may be observed to digest solid food. I have seen an 

 advancing wave of plasmodium, of the same species as that 

 exhibited to the members of the Club, invade a growth of a 

 mould fungus that had spread over the side of a glass box in 

 which the plasmodium was cultivated for observation under the 

 microscope ; the cellulose hyphse of the fungus were dissolved 

 by the plasmodium as sugar is dissolved in boiling water. I 

 have fed the same species with a thick scum of bacteria from 

 water in which portions of a fungus had been steeped for several 

 days. The plasmodium was at once stimulated to increased energy, 

 it poured over the scum in a turgid flow, and shortly after 

 numerous vacuoles in the plasmodium were seen to be stuffed with 

 bacteria : these were probably dead for the most part ; before the 

 experiment was made, they were not wholly absorbed as in the 

 case of the swarm-cell alluded to above, and were often seen to 



