1895.] MICROSCOPICAL JOURNAL. 55 



like bodies, or become joined to them in some way not 

 understood. These form what is called a plasmodium, 

 a portion of which can be seen under the microscope. 

 This Plasmodium is capable of apparently voluntary mo- 

 tion. It goes forward and retreats by a flowing motion 

 carrying embedded in its substance various species of 

 algse which it has captured as food. There is a remar- 

 kable resemblance in the mode of movement between 

 the myxomycetes and the proteomyxa : the same flow- 

 ing motion of the protoplasm and the joining of the fila- 

 ments to form larger ones. 



The reason for the foregoing prelude is that during 

 the month of February 1894 I was watching one of the 

 myxomycetes — which had developed in some water tak- 

 en in the Old Town pond — into what may be called its 

 animal stage. In the glass jar in which it is growing it 

 resembles a miniature tree of many branches, flattened 

 against the glass. Before it made its appearance the 

 glass jar was so covered with growth of algae that one 

 could not see through it. As soon as the myxomycete 

 made its appearance and had traveled a short dis- 

 tance, the glass on that part over which it passed was 

 comparatively clear. Now that the myxomycete has 

 gone several times round the jar, the glass is quite 

 transparent. I took some measurements of its rate 

 of progress: 



Feb. 26, from 2.15 P. M. to 8.45 P. M. it had tra- 

 veled li inches. 



Feb. 27, at 9 P. M. the distance covered was 62 in- 

 ches. 



Feb. 28, at 9 P. M. lOi inches. 



March 1, at 9 P. M. 15J inches. 



So that you will observe the rate of progress is 

 not uniform, but the average rate of progress was 

 5-26ths inch per hour. A curious cicumstance is that 

 while the plant life disappears in all parts of the 



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