CHARACE^:. 79 



Solly, and has been described by Mr. Yarley in one of his 

 excellent memoirs on Char a in the " Transactions of the Soc. of 

 Arts," vol. xlix. p. ii. This deviation occurs in many of the 

 cells which usually surround the seeds, and which are four 

 in number when complete. It occurs, see plate LXI. fig. 1. 

 of the present work, in those cells or sprouts surrounding the 

 seeds marked #, b, c, d, <?, f, g, h, in which the sap has taken 

 a circular or cylindrical course round the axis. Mr. Yarley 

 thus minutely describes this deviation. 



" Fig. 2. (pi. LXI.) is an enlarged view of the sprout a. The 

 circulation is over to the right, as shown by arrows ; it thus 

 far agrees with the spiral course, which is always to the right. 

 Near the point by the top arrow, there is such an accumu- 

 lation as to form a ring or thick mass very like a diaphragm ; 

 this mass keeps revolving on its own axis. Near the second 

 and third arrows the particles are more detached, each going 

 round in its own circle ; here the green studs, instead of being 

 arranged in a straight line, are slightly curved. Still lower 

 down, near the middle of the sprout, there is an inclined 

 elliptical circulation, shown by dots and arrows ; and from the 

 bottom, particles are seen rising nearly as high as the oval, 

 and descending again without appearing to follow any regular 

 course : these are shown by dots and arrows. 



" Some of the particles in sprout (a) were of sufficient 

 size to be distinctly seen during the whole of their revolution, 

 which took place in about fourteen or fifteen seconds : this 

 observation was repeated by different persons, who nearly all 

 agreed as to the time of the revolution ; but in one of the 

 sprouts I observed three particles differing in their speed, 

 and occasionally passing each other. I counted their periods 

 by my own pulse ; one went round in nine beats, the next in 

 eleven ; these followed so nearly in the same track as to 

 move aside whilst passing; the third sometimes occupied 

 twenty beats, and at other times twenty-five in going round. 

 They all appeared to keep to the circumference, and therefore 

 the difference in their periods is more worthy of being re- 

 marked, as seeming to indicate that each particle had some 

 cause of motion independent of the fluid in which it moved." 



