CH. IX THE GERMINATION OF FLOATING SEEDS 77 



littoral plants where germination is not infrequent but always 

 abortive. 



Dealing first with the plants of the mangrove-formation, it may 

 be remarked that the same tendency of the iloating fruits or seeds 

 to germinate, which is above noticed in the case of the estuaries of 

 Fiji, came under my observation in the floating drift of the estuary 

 of the Guayaquil River in Ecuador, the germinating fruits and 

 seeds being carried far out to sea. The seeds of Anona 

 paludosa, which float in quantities in the river-drift, were often 

 found germinating ; and the same may be said of the fruits of 

 Laguncularia racemosa and of the " joints " of Salicornia peruviana 

 which abound in the creeks of the mangrove-delta and are carried 

 out to sea in the germinating condition. 



It might be expected that this readiness to germinate in the 

 brackish water of estuaries would prove to be a formidable 

 obstacle to the dispersal of these plants over wide tracts of ocean. 

 The exposed portions of the seedling might be deemed ill-suited 

 to withstand, without injury, the " wear-and-tear" of transport by 

 currents over long distances, even when not affected by the sea- 

 water ; and it might be thought that they would be often nibbled 

 off by fish or destroyed by other aquatic animals. Only the 

 specially organised seedlings produced by a viviparous process on 

 the tree, such as those of Rhizophora and Bruguiera, might be 

 regarded as able to survive the effects of prolonged immersion in 

 the oceanic currents. 



Observation, indeed, shows that such seedlings are exposed to 

 and suffer from these perils ; j'et it is evident from the distribution 

 of the species that, whether in the germinating condition or not, 

 the seeds and fruits of Anona paludosa and Laguncularia racemosa 

 have been carried by the currents from America to the West Coast 

 of Africa. The seedlings of Avicennia and of Rhizophora mangle 

 have also performed the same trans-Atlantic voyage. Those of 

 both these mangroves are to be observed floating off the coasts 

 and in the estuaries of both coasts of America. The seedlings of 

 Avicennia are particularly abundant in the mangrove-creeks of the 

 delta of the Guayaquil River ; and I observed them in a healthy 

 condition, ten to twenty miles out at sea, floating together with 

 those of the Rhizophora. Since, as in the case of Rhizophora, 

 germination occurs normally on the plant, Avicennia can only be 

 dispersed by its floating seedlings. Yet it is noteworthy that 

 although Avicennia seedlings appear, to a marked degree, less 

 fitted for ocean transport than those of Rhizophora and Bruguiera, 



