TRAVELS IN BRAZIL. 



45 



by Utzschneider and Fraunhofer, showed a number 

 of little bodies, sometimes roundish, sometimes 

 oblong, of the size of a poppy seed. Each of 

 them had at one end, or on the top of the head, a 

 small navel-like opening, having from six to nine 

 fine filaments round it, which float within the 

 bladder, and with which the little animal seems 

 to attach itself to other bodies, and to take its 

 nourishment. In the inside of these bladders we 

 sometimes saw many other small darker points 

 crowded together on one side, or here and there 

 some larger ones, which might be either remains of 

 smaller animals which they had swallowed, or the 

 spawn. These globular animalculae, which are 

 entirely of the nature of medusae, and are mentioned 

 by Peron and Lechenault, under the name of 

 Arethusa ^pelagica^ and by Savigny under that of 

 Noctiluca miliaris, swim in greater or less numbers 

 in the sea water taken up at night, and appear to 

 the naked eye, in the sunshine, like little drops of 

 grease. If the water is not changed, or the ex- 

 amination continues too long, they do not remain 

 in the middle of the glass, but fall dead to the 

 bottom. It is remarkable that these globular animal- 

 culae, when they come near together, involuntarily 

 attract each other, and form whole groups, an effect 

 resembling the magnetic phenomena of inanimate 

 substances. We observed a similar phenomenon on 

 a large scale, in the daytime, here as well as on 

 the ocean. Whole masses of these animals swam on 



