FEEE MESSMATES. 9 



out of the egg are sufficiently developed to be able to 

 provide for their own wants, and to do without a mother's 

 care. 



To return to our animal messmates: let us notice 

 the result of the observations of a learned and skilful 

 naturalist who has rendered great services to ichthyology. 

 Dr. Bleeker has described a still more remarkable 

 association in the Indian seas; it is that of a crustacean, 

 the Cymothoa, taking advantage of a fish known under 

 the name of Stromatea ; too imperfectly organized to fish 

 for itself at large, but more skilful in snapping up all 

 that comes within its reach, it makes its home in the 

 buccal cavity of the Stromatea. 



But of all crustaceans, the most cruel is the isopod 

 named Ichthyoxena, which hollows out for itself and its 

 female a large dwelling-place in the coats of the stomach 

 of a cyprinoid fish. We will return again to these 

 examples. 



The Physaliie, those charming living nosegays of the 

 tropical regions, also give lodging in their cavities, and in 

 the midst of their long cirrhi, to little adult and perfect 

 fishes, belonging to the family of the ScombricUe, a family 

 to which are attached the tunny and the mackerel. These 

 sea-butterflies flutter away their indolent existence at the 

 expense of their host. Voyagers tell us that they have 

 seen them by dozens concealed in these animated fes- 

 toons. Mons. Al. Agassiz has mentioned, in his illus- 

 trated catalogue, another fact, quite as extraordinary, 

 observed in the Bay of Nantucket, in the United States ; 

 it relates to a nocturnal Pelagia (Dactylometra quinque- 

 cirra, Ag.) always accompanied, not to say escorted, by 

 a species of herring. The two neighbours constitute 



