MUSSEL CLIMBING. 335 
was pressed against the glass. Again the foot was with- 
drawn a little, the lips of the groove unfolded, and the 
moulded thread set free. This gave thread number two. 
Each was evidently set at a considerable tension. And in 
this wise, thread after thread was formed and set. I regret 
that I did not record the exact number, but am sure that it 
was about twelve or sixteen, and the time occupied was be- 
tween two and three hours, when lo! up went the mussel, 
about three-eighths of an inch high. Yes, he was drawn up 
by his own cords. He was literally lifted from terra firma. 
Not at all suspecting what was to follow I mentally ex- 
claimed. “This little fellow knows the ropes." 
There was next a period of rest. Whether it was due to 
exhaustion of material, and was meant to allow the secreting 
gland time to evolve a fresh supply or not, I cannot affirm ; 
but must say that such was my belief, for after an hour or 
so it set to work again, precisely as before, attaching a new 
cluster of threads. This cluster was set about five-eighths 
of an inch higher than the previous one. When this new 
group of filaments was finished, the same result followed, 
another lift of a fraction of an inch, but not quite so high as 
the first. I now suspected its motive—the animal was 
actually in this singular manner attempting to reach the sur- 
face. It wanted to take an airing, and was really in a fair 
way to bring it about. 
While setting its third cluster of threads, I foresaw a seri- 
ous diffieulty in the way, and one against which the spider 
never has to contend. It was this: after the third lift had 
been achieved the threads which had accomplished the first 
lift had changed direction; that is, the ends of the threads, 
Which had pointed downward when pulling up the mussel, 
were now pointing upward, and were actually pulling it 
down. Of eourse the lowermost thread, or threads, would 
exert the most retrograde traction. Thought I, *Sir Mussel- 
man, you will have to exercise your wits now.” I rejoice to 
say that the ingenious little engineer was complete master 
