LEMANIA. 69 



be pressed between the fingers, their contents N will be forced 

 out : on examining which, with the microscope, the observer 

 will be astonished to perceive that it is made up of a number 

 of beaded and plant-like bodies, which the inquirer would be 

 inclined, at first sight, to regard as the species in its young 

 state : this opinion, on further investigation, would be found 

 to be erroneous ; for if these tufted bodies be watched, and 

 kept in water for some time, the beads of the filaments will 

 soon be perceived to separate from each other, and each ul- 

 timately to become developed into a young plant resembling 

 that from which the seed was derived. The separation of 

 the sporules which compose the beaded threads likewise takes 

 place naturally within the frond, and it is by their develope- 

 ment that the dilatations of the stems, already referred to, 

 are produced, and by which an apparent resemblance to the 

 Batrachosperms is imparted to the plants of this genus. 



Frequently, if these dilatations be examined with a lens, 

 numerous filaments may be observed issuing from them : 

 these are what Vaucher terms the young polysperms pro- 

 duced by the germination of the sporules, which are still 

 within the frond, and which developement of them is or- 

 dained to take place in all cases to such an extent as to 

 occasion the rupture of the dilatations, and consequent separ- 

 ation of some of the cortical cells from each other ; thus, 

 apertures are created, through which the sporules may pass 

 out, a condition essential to the perpetuation of the species. 

 The force with which this developement operates may be 

 appreciated when the cartilaginous nature of the frond is 

 considered. 



It is only the middle and upper branches that are so 

 torulose, the lower being almost plain and cylindrical ; this 

 arising from the fact of the sporules having all escaped from 

 these, which are the oldest portions of the plant. 



Bory's account of the structure of this genus appears 

 to contain some strange errors. " The Lemanice" he remarks, 

 " are articulated Conferva, whose contiguous joints are 

 united the one to the other by a solid interior filament, very 

 well represented by Vaillant (Bot. Paris, pi. iv. fig. 5.) in 



F 3 



