FREE MESSMATES. 19 



Cuvier did not believe that the pinnothere brought 

 any food to the mollusc, since the latter, in his opinion, 

 lives entirely on sea-water. 



Other zoologists regard the pinnothere as an intruder 

 whom chance has brought into this mysterious position. 

 Others again consider mussels as acquaintances possessed 

 of a very curious disposition, and that having no eyes, 

 they have interested in their fate this little crab, which is 

 perfectly provided with eyesight. In fact, in common 

 with other crustaceans of his species, he carries on each 

 side of his carapace, at the end of a movable stalk, a 

 charming little globe, provided with some hundreds of 

 eyes, which he can direct upon his prey, as the astro- 

 nomer turns his telescope on any point of the firma- 

 ment. These later natm-alists consider, in fact, their 

 crab as a living journal which supplies his host with 

 the news of the day. Eumphius, a Dutchman, the 

 first who described the animal of the nautilus, also 

 understood the habits of pinnotheres. In his *'Am- 

 boinche Eariteit Kamer," pubhshed in 1741, he says 

 that these crustaceans inhabit always two kinds of shell- 

 fish, the Pinna and the Chama squamata. According to 

 him, when these molluscs have attained their growth, 

 one pinnothere (one only at least in the Chama) lives in 

 their interior and does not abandon its lodging till the 

 death of its host. Eumphius regards this crustacean as 

 a faithful guardian, fulfilling the duties of a door-keeper. 

 In 1638 he found actually two sorts of keepers : by the 

 side of a Brachyuron, carrying an embossed buckler, 

 slender in front, he discovered a Macrouron of the length 

 of his finger-nail, of a yellowish orange colour, semi- 

 transparent, with white and very slender claws. It is 



