xxx RHIZOPHORA 453 



RHIZOPHORA MUCRONATA. 



Growth of the first seven inches of the hypocotyl after it protrudes 



from the fruit. 



IO lines (25 mm.) after 26 days 



20 (50-5 mm.) 41 



30 (76 mm.) 51,, 



40 (101-5 mm.) 61 



50 (127 mm.) 70 



60 (152 mm.) 78 



70 (W5 mm.) 86 



In my description of the germinating process of Rhizophora 

 mangle from this particular standpoint I adopt the general views of 

 Prof. Schimper, the observations being my own, the phraseology 

 employed being his. It would be out of place here to deal with the 

 biological significance of a process to which observers like Warming, 

 Goebel, Karsten, Schimper and Haberlandt have applied their 

 greater talents as well as their greater experience. I investigated 

 the subject carefully from my own standpoint of inquiry, and whilst 

 the reader will find in my rough sketches of the various stages of 

 the process a little aid in following the argument, he is referred for 

 detailed treatment of the subject to the memoirs of the above-named 

 botanists as well as to those of yet more recent investigators. 



After fertilisation, according to Prof. Schimper (Ind. Mai. Strand- 

 flora], the embryo-sac is filled with endosperm, which subsequently 

 protrudes and forms a plug completely closing the micropyle (see 

 my figures). As my observations showed, the seed during the first 

 eight weeks after fertilisation increases continuously in size, and the 

 plug of endosperm, at first inconspicuous, becomes of considerable size, 

 the seed attaining a length of seven millimetres. The embryo mean- 

 while grows rapidly, and at the end of this period of eight weeks the 

 radicular tip or the point of the hypocotyl begins to protrude from 

 the micopyle, still covered by the plug of endosperm, the fruit being 

 between four and five lines (10-12 mm.) in length (figures 11-14). 

 In another week, when the fruit has grown another line in length, the 

 -ip of the radicle is on the eve of piercing the plug, and this may be 

 rmed the commencement of germination, nine weeks after the act of 

 rtilisation. The next stage, after an interval of one and a half 

 weeks, is illustrated in figure 15 ; and after a period of about fifteen 

 weeks from the date of fertilisation the tip of the radicle pierces the 



