2 8o Dzvellers of the Sea and Shore 



tion rapidly grows deeper, finally separating the crea- 

 ture into two equal parts, each part a smaller but exact 

 duplicate of its single prototype. Thus where there 

 was one adult mother cell, there follows in her place a 

 younger pair; and these twin daughters will in their 

 turn, when they get older, proceed to divide likewise. 

 In this manner the cycle continues. But it may be 

 pointed out that this method of ^reproduction by fission, 

 as it is called, does not always continue indefinitely 

 without a variation. During some succeeding genera- 

 tion two individuals will come together and a fusion of 

 their nuclei will take place, the flagella disappear, and 

 the pair seem to coalesce into a single body; reversing 

 the process of division, so to speak. Eventually, how- 

 ever, the fused nuclei split into numerous pieces and 

 pass to the surface of the sphere where they form prom- 

 inences, or buds, which ultimately become detached and 

 swim away as zoospores, or young Noctilucas. When 

 these grow up they will divide, and their descendants 

 for a greater or lesser length of time will also continue 

 to reproduce in this way. 



The color of light emitted by Noctiluca varies with 

 the different species; still sometimes a single species will 

 be found to give forth light of different hues. The 

 beauty and intensity of the Hashes are marvelous, 

 coming from so small a creature, and their nature has 

 been the subject of much investigation. But man has 

 as yet vainly endeavored to capture its secret. He has, 

 indeed, been able to isolate the chemical compounds 

 which are the source of light, and has even given them 

 a name, but of their ultimate nature he is still very 

 much in the dark. The term "phosphorescent" ap- 



