COURTSHIP AND DISPLAY 203 



ficial resemblance of form to spiders, but in some habits 

 are like them, though the Cephalopods are molluscs 

 allied to snails and mussels, and are quite unlike spiders 

 in deeper structure and remote from the whole group of 

 hard-skinned, jointed-legged animals such as crustaceans, 

 spiders, and insects. I once had the chance to see a 

 male octopus " displaying " to a female in one of the 

 tanks of the aquarium at Naples. There were a male 

 and a female already living there when we introduced 

 from another tank a second male, which had just 

 destroyed and fed upon a large lobster, who had him- 

 self, with no evil purpose, crushed the head of a 

 Mediterranean turtle foolishly placed by that animal 

 between the open fingers of the lobster's big nippers. 

 The new arrival promptly drove the earlier tenant 

 octopus out of the tank. He pursued his rival round 

 and round with great rapidity until the latter leapt 

 from the surface of the water (by a violent contraction 

 of the mantle) and escaped into the adjacent tank. 

 Then the triumphant intruder approached the female — 

 floods of changing colour, reddish-brown, purple, and 

 yellow, passing over the surface of his body — and com- 

 menced an extraordinary display with his eight long 

 sucker-bearing arms. He made these wind into close- 

 set flat spirals and again unwind and gracefully trail in 

 the water, when they immediately wound up again in 

 spiral coils. The female watched this proceeding for 

 more than an hour, and then they embraced. I could 

 not follow any further details, but a few days after this 

 the female piled up a number of stones, so as to make 

 a nest in shape like a shallow basin. We enticed the 

 male into a net and placed him in another tank, so that 

 he should not be able to molest the female or to devour 

 her offspring, which he would do if he had the chance. 

 Then the female laid her eggs — minute oval, transparent 



