554 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



BIONOMICS AND ECONOMICS. 



The hermit crab has suffered from the neglect so 

 commonly meted out by competent zoologists to animals 

 whose peculiar habits have attracted the attention of the 

 unscientific observer. There is consequently a large 

 mass of undigested facts and fables concerned with its 

 mode of life and habits, and an equal paucity of 

 accurate morphological data. The most remarkable 

 precocity has been attributed to this creature, with no 

 regard for the comparatively lowly position it fills in the 

 animal series. 



I have not come across many early references to the 

 hermit crab. Aristotle notices two species — probably 

 E. bernhardus and Diogenes varians — briefly and 

 indifferently well. He found them in the shells of 

 Strombus, and remarks on the softness of the exoskeleton, 

 the fact that they are not attached to the shell they 

 occupy but change as they outgrow it, their possession 

 of an oesophagus which leads into a stomach — there is 

 no recognition of a gut or an anus — and finally, the 

 astonishing statement that some anomuran, it is not clear 

 which, casts a web across the mouth of its habitation to 

 capture its prey. He considered these animals to be 

 intermediate between the Mollusca and Crustacea, and 

 that they originated, like the former group, from mud 

 and sand. 



Swammerdam (1738) was the first to make a 

 scientific investigation of the hermit crab's anatomy, 

 and except for one terrible mistake (referred to below) 

 his work was very advanced. The account of the nervous 

 system is especially good, and his careful dissection 

 prevented him falling into the serious errors committed 

 by Gegenbaur and Claus, among others, which have 

 found their way into modern text-books. 



