254 



FRUCTIFICATION OF FUCUS. 



PAET II. 



coats are united at the base, and when the spores are ready 

 for dispersion, the inner coat bursts through the apex of 

 the outer one, dragging with it a portion of the latter in 

 the form of a little peduncle. The immediate covering of 

 the spores at length bursts, and they are set free.' 3 In 



Fig. 31. Vertical section of receptacle of Fucus platycarpus. 



Fucus serratus, vesiculatus, and nodosus, swarms of 

 spermatozoids are produced, but M. Thuret has proved 

 by experiment that they never come to anything of 

 themselves, and the unfertilized spores perish. 



When a fertilized spore begins to grow, it assumes a 



8 In the Fuel each kind of fruit is discharged on the surface of the 

 receptacle before fructification. 



