Marine Groves and Gardens 129 



reproduction which is later to be found in such per- 

 fection among higher plants. In fact, this alga carries 

 on its spore production in a way that is ah'eady as 

 involved as the formation of seeds in flowering plants. 

 The conceptacles are usually grouped at the extremities 

 of the frond, and are easily identified, as their surface 

 has a pimpled, or rough, appearance. Now Fucus is 

 heterogamous; this means that the individual plant 

 bears both the male and the female sex organs. The 

 eggs and sperms are discharged in the water inde- 

 pendently. The eggs float freely and without motion; 

 but the sperms each possess two cilia arranged in a 

 fore-and-aft manner, and these latter, being in a con- 

 stant state of vibration, enable the organism to swim 

 about. So small are these sperms that many hundreds 

 can be contained in a drop of sea water. The eggs 

 are considerably larger, though their details cannot 

 be resolved without the aid of a good microscope. As 

 the egg floats passively in the water, in some mysterious 

 way — supposedly by chemical action — it attracts great 

 numbers of male cells to it, and these arriving in such 

 force, frequently set it to rotating by impinging against 

 it. Yet of all the host that seek it, only one is 

 favored. A fusion finally takes place, and the now 

 fertile egg drifts around for a while, eventually finding 

 a favorable lodging place on some rocky shore where 

 it later develops into a new plant. 



As Fucus must find a firm support to which to attach 

 itself, it is obvious that its presence on the Atlantic 

 coast would be relatively rare south of Long Island, 

 for below this region great stretches of sandy beaches 

 prevail. There does exist, however, in the deeper 



