APPENDIX. 



1. PAGE 5. Noctiluca. This interesting little creature belongs, in 

 the natural arrangement as now recognized by science, to the first grand 

 division of the animal kingdom. Simple as it is, it is not so completely 

 without organs as some which form the first groups of this first division, 

 as it has a whip-like organ, which gives name to its group, the Flagellata, 

 or flagellate infusorians. These monads, as they are also called, are 

 represented by a species of Noctiluca in our North- American waters off 

 the coast of Maine. Huxley regards its luminous property as given out 

 by the peripheral layer of protoplasm which lines the cuticle. 



M. Giglioli of Bologna, Italy, in a letter to the author, says, " I have 

 distinguished three modes of marine phosphorescence, very distinct, 

 which present a great number of varieties. These are, 



" (a) Diffused homogeneous milky light. 



" (b) Luminous points, sparkling and inconstant. 



" (c) Luminous disks, with light generally fixed, and not sparkling. 



" In one case the sea seemed on fire, and dolphins seemed to be fire. 



"Again, the sea seemed to acquire an oily consistence, giving out soft 

 homogeneous light, of a milky color, tinted with green or bluish. It is 

 perhaps the least frequent, but most striking. It is due to the presence 

 of noctiluca. It often resembled incandescent rain falling from the 

 paddle-wheels of steamers.'' 



M. Giglioli agrees with Huxley in stating that " the phenomenon of 

 phosphorescence in these animals does not reside in the protoplasmic 

 branches, which, as is known, are sometimes wanting; but in the corti- 

 cal substance it is not uniform, but manifests itself in distinct and very 

 minute luminous points, which sparkle, go out, and light up again." 



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