166 THE- PKAWNS. 



is in tlie interior of tlie globose compound eye. The 

 reflection is seen whatever part of the eye is opposite 

 the light (provided it be facetted, of course), but is 

 most full direct in front, where no unfacetted portion 

 can be seen. Yet it certainly has no connexion what- 

 ever with reflection from the exterior surface, as might 

 be suggested by any one who has not actually seen 

 it : the effect of this would be a minute point of light, 

 very different from this broad round gleam. 



The different species of Pagurus, and some Crabs, 

 as Portunus^ exhibit the same phenomenon, but in a 

 lower degree ; the disk of light being smaller and of 

 less brilliance ; though their eyes are larger. I have 

 seen the same appearance in the eyes of Moths and 

 other nocturnal insects ; so that doubtless it is de- 

 pendent on the common structure of facetted com- 

 pound eyes. 



It is pretty to see the Prawn fed. When a morsel 

 of food is dropped through the water near its head, 

 the excessively long antennas (especially the long 

 filaments of the superior pair, which are carried per- 

 pendicularly upwards) seem principally to take cogni- 

 sance of its presence and of its qualities. The eyes, 

 though evidently alert, are, I think, less trusted. As 

 the morsel comes within reach, the second feet, the 

 principal organs of prehension, are stretched out, with 

 the two fingers (pincers) widely extended ; these seize 

 it with the most easy action possible, and in a moment 

 thrust it towards the mouth. 



