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where the ground is widely covered with the well-known asparagus- 

 like grey pneumatophores. 



Here on an old Avicennia-ivee (fig. 8) numerous aerial roots 

 were descending from the main stem and from the under-side of 

 the branches. These roots were much branched, foot long, in their 



Fig. 8. An old Avicennia-hee with aerial roots, from (lliristianssteds Lagoon. 



(F. B. phot.) 



ramifications very similar to those of lihizopliora. As in the case 

 of Rhizophora, the main root ceases to grow and new side branches 

 arise a little above its point; they only' seem to grow very slowly, 

 and scarcely ever reach the ground. 



On St. Jan in the mangrove vegetatii. n of Great Cruzbay, I 

 have seen another Avicennia-ivee (fig. 9) with quite similar aerial 

 roots (fig. 10). Professor V. A. Poulsen has examined the anatomical 



