On Azolla and Salvinia, 247 



agent determining their subsequent development ; that deve- 

 lopment is continued contemporaneously ; they separate con- 

 temporaneously, and without either having undergone any 

 particular change. So that if they be male and female, 

 the action of the one on the other does not take place while 

 they are attached to the axis. 



There appears to me absolutely nothing in the structure 

 of the supposed male to suggest its performing the functions 

 of that sex. I believe that in cases of the known male organs 

 of vegetables the (active) contents are homogeneous, the 

 functions ephemeral. Dr. Martius (op. cit. p. 127 J is of 

 opinion that the lobed bodies have nothing of the char- 

 acters of anthers, and that the whole contents form the 

 rudiment of a young plant, grounding this opinion on the 

 similarity of the sac or vesicle with the nucula of Chara 

 and Marsileaceae. But it is remarkable that he considers 

 the masses of the other secondary capsules, which are solid 

 bodies, to have the closest analogy with pollen grains, and 

 therefore he alludes to his having observed them adhering 

 firmly to the calyptrate capsule. 



An argument in favour of their being male organs is 

 derivable from the development, which appears to be that 

 of the pollen of phaenogamous plants. But this holds good to 

 a greater degree in the development of the contents of the sup- 

 posed female, as well as in that of the acknowledged spores of 

 some other Acotyledonous families, in which nevertheless the 

 evidence in favour of sexes is acknowledged to be the most com- 

 plete. The same argument, so extended as to include both 

 kinds of bodies, may be advanced. In this case they will 

 enter the hypothesis of Mr. Valentine,* which must, how- 

 ever, to be consistent with analogy suppose the absence of 

 sexes in all Acotyledonous plants. This I think difficult 

 to do, and while I fully agree in the remarkable similarity 



* Linn. Trans, xvii. p. 480, 481 ; xvih. p. 502. 



2 K 



