INTRODUCTION. XXV11 



partially to become dry, drops of an orange, viscid liquid 

 will ooze out of the pores of the conceptacles, and collect 

 on the surface. If a small portion of this fluid, diluted by 

 a drop of sea water, be now placed under the microscope, 

 it will be found to consist of myriads of detached antheri- 

 dia, in all stages of fullness, among which troops of sper- 

 matozoa will be seen performing their strange gyrations. 

 Such is the nature of the supposed male system of the 

 Fuci. Its analogy with the antheridia of the mosses is 

 obvious, but observations are still wanting to show that the 

 spermatozoa in either case have any connexion with the 

 fecundation of the spores. If we limit our assertions by 

 the present state of our actual knowledge on the subject, 

 all that we can state with certainty is, that in those cases 

 where the formation of spores among Algae has been most 

 closely watched and most successfully observed, the spore 

 has resulted from the union of the contents of two cells. 

 That a transmission of the endochrome from one cell to 

 another, prior to the formation of spore, occurs in all the 

 compound Algae, seems probable from the fact that the 

 cells immediately surrounding the spores are always co- 

 lourless and empty, but there is nothing as yet known to 

 prove that one cell is less adapted than another to receive 

 the endochrome, and form the future embryo, nothing to 

 show that there is any clear distinction into male and 

 female. 



Experiments on the propagation of Algae from their spores 

 have not yet been so frequently made as the interest of the 

 subject deserves. In our own country, I am not aware that 

 any one since Mr. Stackhouse, in 1796, has attempted it. 

 This gentleman attempted to grow some of the Fuci, and 

 so far succeeded with F. canaliculatus as to witness the 

 germination. The following account of his experiment, 

 which I extract from his ' Nereis BritannicaJ though 



