Fig. 1. 



Biccia nata 



Fig. 2. 



» J) 



Fig. 3. 



5> 35 



Fig. 4. 



JJ 5J 



Fig. 5. 



JJ 5J 



Fig. 6. 



)J 55 



Fig. 7. 



55 55 



Fig. 8. 



55 35 



BY E. A. BASTOW, F.L.S. 37 



Tinder tlie microscope ; the drawing of the American 

 plant is also on the table, so the members of the 

 Society may compare the plants for themselves. If our 

 M. natans is not a native of Tasmania, but has followed in 

 the wake of civilisation from Great Britain, it has wonderfully 

 improved by the change. If injurious plants thus imported 

 increase in vigour in a similar ratio it will be advisable to 

 keep a sharp look out for the first appearance of any of 

 them and at once destroy them. 



Explanation op Plate I. 

 nat. size, 

 spores magnified, 

 nat. size, North American. 

 Tasmanian, mag, 7 diam. 

 Tasmanian, serrations oi fimhrice, Jin. obj. 

 ,, . „ „ fin. obj. 



JN ortli American, magnified. 

 Tasmanian, upper surface of frond, 

 ■gin. obj. 



Fig. 9. „ „ JSTorth American, sect, through frond, 



showing immersed capsule containing 

 spores. 



Obseev. on Nitella. 



I have placed a fragment of Nitella on the stage of one of 

 the microscopes in order that the rotation of the protoplasmic 

 fluid may be observed. 



It has been found inscribed in the " Book of the Strata " 

 that there are forty species of the Katural Order Characese 

 met with from the Triassic to the Tertiary, so that from a 

 remote period of time masses of this most curious order of 

 plants have vegetated in the lagoons and sluggish fresh water 

 streams of temperate climates. The Order is remarkable for 

 the singular nature of its reproductive bodies, and for the 

 distinctness with which the circulation of the fluids may be 

 seen ; on this account it possesses a peculiar interest to 

 microscopists. The fluid passes steadily up one side of the 

 internode and down the opposite side, it carries granules of 

 starchy matter along with it, and these granules appear at 

 times to rotate on their own axes as they pursue their course 

 around the interior of the internode. The movement may be 

 due to diffusion of gases required by the plant, through the 

 cell-wails, but if that is the case, diffusion goes on at com- 

 paratively excessive speed. The rapidity of the movement may 

 perhaps be accounted for by the size of the cavity between 

 iihe nodes of the stem and the continual change in temperature 

 and barometric pressure, the rotation being easily accelerated 

 by warmth or rendered sluggish by cold. 



