of the Fishery Board for Scotland. 



175 



This curious action was most purposive and effective. The current 

 created was so strong as to sway the algsB growing on the side of the tank 

 in the neighbourhood as well as the tentacles of the anemone, and even 

 to cause the whole mass of eggs to rock visibly backwards and forwards. 

 This action was done at brief intervals and from this time onwards. 

 Later, when the eggs were hatching it was redoubled, and great activity 

 was shown with the fins. The movement thus created in the water very 

 probably helped the escape of the larval fishes from the eggs. At this 

 time the "pumping" or "blowing" action was at the rate of fifteen or 

 sixteen in ten seconds, and in the pauses the fins were kept vigorously 

 at work. 



On April 17th, I tried an experiment. I removed the devoted lump- 

 sucker in a dip-net and placed him in an adjoining tank of the same 

 dimensions, in which were a few dabs (which were greatly alarmed). 

 After turning round once or twice, as if to get his bearings, he swam 

 towards the corner where he expected the eggs to be and paused about a 

 foot away. He then swam up to a stone at the back of the tank and 

 paused again ; he next moved restlessly all round the tank, and came 

 back once more to what appeared to be the familiar corner ; then he 

 moved slowly towards the other corner and lay quietly on the bottom, 

 having apparently abandoned the quest. 



Meantime, I endeavoured to get the other male to undertake the 

 guardianship of the eggs. He was driven gradually to the corner where 

 they lay, and paused a moment, but rather, it may be conjectured, with 

 surprise at the absence of his foe than from any impulse to attend to 

 them. The experiment was repeated with a like result, no inclination 

 being shown by this male to assume the duty. Whether he would have 

 done so later may only be conjectured. Finally, I placed this male in 

 the other tank beside the proper guardian in order to see whether the 

 latter would attack him in the absence of the eggs. He did not. He 

 merely looked at him, without making any attempt to approach or 

 pursue him. On the other hand, the newcomer recognised his enemy, 

 and rushed off as before, but finding that he was not pursued, he soon 

 settled down and approached the other male, who took not the least 

 notice of his presence. 



Both males were then put back into the tank containing the eggs. The 

 guardian at once sought for them and resumed his duty, and with it 

 also his animosity to the other male, and the old relationship was 

 re-established. 



Towards the end of April the conditions were the same as before, the 

 sentinel lumpsucker " blowing " and fanning the eggs, refusing mussels, 

 removing them from near the eggs if dropped there, chasing away 

 wandering flat-fishes and relentlessly pursuing the other male, and coming 

 up angrily and aggressively when one approached the front of the tank. 



By this time the egg masses had become very dark, owing to the 

 development of black pigment in the now well-advanced embryos. The 

 masses at first, as stated, were pink ; this tint faded and they appeared 

 pale green, whitish, then dirty amber-coloured, and then dark, for the 

 reason mentioned. 



The colours of the males were also different. The one that was 

 guarding the eggs, and had probably fertilised them, had lost his bright- 

 ness and was dingy, while the other,who most likely had not spawned, 

 possessed the red colour on his fins and lower part as vividly as at first. 



More than a month had elapsed since the guarding male assumed duty, 

 and during that time he had eaten nothing. He was looking thin and 

 and was infested with ecto-parisites yCaligi), and appeared sometimes 



