LOCH C RE RAN. 



the greater proportion of individual butterflies are white ? 

 At present it is quite an exception to see a dark-coloured 

 one, while the white of various species are legion. That 

 a white butterfly is as readily observed by a bird as any 

 other, we are as satisfied as we are that it is more readily 

 noted by the human eye ; so it cannot be to escape its 

 enemies. Is it really from a wholly opposite necessity 

 that of being observed by its fellows ? This is, perhaps, 

 more than probable; and as they jerk along over the 

 heath, or flutter so jauntily and aberrantly over the fields 

 of oats until they recognise their " affinity," you conclude, 

 as they tumble together into the vegetation, that it is 

 more important for the race, with us, to be readily 

 recognised, than to be specially fitted to escape obser- 

 vation. 



Very frequently we have brought up in the dredge, a 

 smooth species of sponge, in which a hermit crab is en- 

 sconced, and we have wondered how and why it should 

 have selected such a situation. The peculiar shape of 

 the sponge at length satisfied us that it must have origin- 

 ally started from a shell, but again and again no shell has 

 been found inside. We find, however, that it does seem- 

 ingly start as a growth upon a miniature shell, in which 

 the crab has placed itself, and gradually the sponge has 

 eaten away the shell, but had no effect upon the movable 

 body of the crab. Nothing could better prove the effect 

 of sponges upon shells than this case, in which it ends 

 by entirely removing all evideuce ot there ever having 

 been a shell at all. Other sponges seem to act more 

 slowly, as those upon oyster and scallop shells, but even 

 these puncture holes all over the shell, and gradually 

 disintegrate as they continue to penetrate. 



The evening is remarkable still, the tide very high, and 



