FLIES— CRABS 
231 
preserver having invited a friend to dine and sleep at liis house, 
the fly, the next morning, perched upon the thumb of the 
visitor, who, being ignorant that it was a pet of his host’s, 
clapped his hand upon it, and thus put an end to Mr. Slingsby’s 
experiment . 1 
Crustacea . 
There is no doubt that these are an intelligent group 
of animals, although I have been able to collect but 
wonderfully little information upon the subject. Mr. 
Moseley, F.K.S., in his very interesting work, 6 Notes by a 
Naturalist on the Challenger says (p. 70) : — 
In the tropics one becomes accustomed to watch the habits 
of various species of crabs, which there live so common ly an 
aerial life. The more I have seen of them, the more have I been 
astonished at their sagacity. 
And again (pp. 48-9): — 
A rock crab ( Grapsus stringosus) was very abundant, run- 
ning about all over the rocks, and making off into clefts on one’s 
approach. I was astonished at the keen and long sight of this 
crab. I noticed some made off at full speed to their hiding- 
places at the instant that my head showed above a rock fifty 
yards distant. . . . 
At Still Bay, on the sandy beach of which a heavy surf was 
breaking, I encountered a sand crab ( CEcypoda ippeus ), which 
was walking about, and got between it and its hole in the dry 
sand above the beach. The crab was a large one, at least three 
inches in breadth >f its carapace. . . . With its curious column- 
like eyes erect, the crab bolted down towards the surf as the 
only escape, and as it saw a great wave rushing up the shelving 
shore, dug itself tight into the sand, and held on to prevent the 
undertide from carrying it into the sea. As soon as the wave 
had retreated, it made off full speed for the shore. I gave 
chase, and whenever a wave approached, the crab repeated the 
manoeuvre. I once touched it with my hand whilst it was 
buried and blinded by the sandy water, but the surf compelled 
me to retreat, and I could not snatch hold of it for fear of its 
powerful claws. At last I chased it, hard pressed, into the 
surf in a hurry, and being unable to get proper hold in time, it 
was washed into the sea. The crab evidently dreaded going 
into the sea. . . . They soon die wdien kept a short time be* 
ueath the water. 
Gleanings , vol. ii., pp. 165-6. 
