166 



THE YOUNG NATURALIST. 



the question, but I am endeavouring to work it out; The tubes do not seem 

 to be in close contact enough with the annelids to be secreted, and there 

 appears to be nothing analogous to the mantle of the mollusca. I am of 

 opinion they do build their tubes up and do . not secrete them, we always find 

 them where there is abundance of carbonate of lime about, as on oyster shells, 

 calcareous rocks, and such like, and even when they are on other substances 

 not calcareous, there is sure to be plenty of carbonate of lime in the im- 

 mediate neighbourhood. 



Look at the extraordinarily rapid way in which that whelk shell is moving 

 along, quite different from the normally slow manner in which Buccinum 

 undatum progresses. It is, however, easy to explain the mystery. Let us 

 pick it up. We see it is no whelk at .all, but only the dead shell of that 

 well-known mollusc, tenanted by the, to all keepers of an aquarium, familiar 

 crustacean Pagtirus Bernhardt. The hinder part of this creature is soft, and 

 unprotected by the coat of mail with which the limbs and fore part of the 

 body is guarded, it is compelled therefore to ensconce its tail in some empty 

 shell or other. Large individuals like this one take possession of a dead 

 whelk shell, smaller ones may be found occupying Nerita, winkle, or Trochus 

 shells. 



Hermit crabs are very amusing pets in the aquarium, and I have had 

 numbers of them. I feed them on scraped beef, which they readily take from 

 a quill. They soon get on familiar terms with me, and when I have them 

 in a vase will often tap on the glass with their claws as if to attract my 

 attention, and sometimes they will follow the movements of my finger out- 

 side the glass. They see best upwards however, and if the quill is moved 

 about above them they will stretch out their claws to reach it even if it has 

 no meat on it. I had one for over two years. When I first captured it, it 

 was a tiny individual, and was domiciled in a small shell of Trochus zizy- 

 phinus. After it had exuviated for the first time in my aquarium, it changed 

 into a yellow periwinkle shell and in this it remained many weeks. At first 

 it was very shy, and retreated into its domicile on the instant it caught sight 

 of me, and only by remaining perfectly motionless could I observe it move 

 about, which it did in a very comical way, generally carrying its domicile 

 sideways in rather an awkward manner as if it were too heavy for it. After 

 I had had it a week or two it got more accustomed to me and would accept 

 a morsel of scraped meat if offered on a quilt. In time it got so tame and 

 familiar as to beg for food, and would permit me to watch its movements, 

 and even examine it with a lens without exhibiting the slightest fear. In 

 common with other hermit crabs it had a very curious way of beating the 

 water with its antennas, which was very interesting to watch. It loved very 



