316 Luminousness of the Sea. 



ments for examination. About the centre of each tube or 

 division there appeared a dent or depression, marked by a 

 dark line, and in this hollow lay a small round body like an 

 ovum. Nearer the extremities, also, were to be seen a num- 

 ber of small round bodies, shaped like nails and pretty regu- 

 larly disposed. In some, as in a, the tubes or joints seemed 

 almost detached from each other, except where they were 

 united by a small point. In others, as in b, they seemed to 

 enter each other by a sharp point at the extremity ; this dif- 

 ference most probably arising from the position of the objects 

 while under examination. The natural size of each joint 

 appeared to be not larger than a grain of sand. The other 

 body (Jig. 83. c) only occurred once to me, and it appeared 

 also to be a fragment. It was coiled round in a circular 

 manner like a snake, not forming a perfect circle, as the 

 extremities, which were both open, did not meet. Through 

 its whole length it was separated into a great many divisions or 

 short tubes, each band of division or septum being double, and 

 each division containing a dark spot in its centre like an ovum. 

 Natural size about the sixth of an inch in circumference. 



These eight species of animals all belong to the ^calepha 

 of Cuvier ; but there are other animals, more perfect and of a 

 higher organisation, which have also been found to produce 

 this luminousness in the sea. Several of these I have already 

 mentioned, as two or three species of Ccincer, &c. ; but there 

 are also a good many of the Crustacea, belonging to the order 

 Entomostraca of Muller, which possess this property, a few 

 of which I have already mentioned, as the Limulus noctiliicus, 

 an animal described and figured by Macartney (although, 

 according to Leach, this insect is not a Limulus, but a species 

 of a genus unknown), and the Lynceu5, which is described by 

 Riville, and which Muller says very much resembles his L. 

 brachyurus. While engaged in examining the animals I 

 have just described, several species belonging to this order, 

 became known to me, some of which were abundant at the 

 times that the sea was most luminous, while others, again, 

 occurred only occasionally. Some of these are evidently 

 luminous, others did not appear so : but, as it is well known 

 that these little creatures have the power of giving out or re- 

 taining their luminousness at pleasure, it is not surprising that 

 in many instances it escaped my notice ; especially as they 

 are extremely shortlived, dying very soon after being taken 

 up out of the sea. The observations, too, of several naturalists 

 of late, as Dr. Macculloch, go far to prove that the property of 

 giving out light is in all probability possessed by all these 

 little inhabitants of the deep ; and, as this faculty is evidently 



