742 



SCIENCE 



[N. S. Vol. XLI. No. 1064 



I would fain let sliunber. The material 

 whifih but a short time before had been on 

 the bottom at a temperature but little above 

 the freezing point was unpleasantly cold to 

 handle. Then there was the ever-present 

 discomfort caused by the rolling of the 

 vessel, accentuated to a stomach-racking 

 degree by the motion communicated to the 

 vessel when the dredging was in operation. 

 Under such conditions it should not be a 

 matter of wonder if from time to time the 

 most zealous of naturalists turned away 

 from the large seive, into which the mate- 

 rial from the trawl was emptied, with feel- 

 ings akin to those experienced by the fishes 

 just before they lost consciousness as they 

 were being hurried from the bottom. These 

 fishes came to the surface with either swim- 

 bladder or stomach protruding from their 

 mouths, and their eyes starting from their 

 sockets. Such phenomena are due to the 

 enormous release of pressure experienced in 

 being in a few minutes transferred from the 

 bottom to the surface, a difference approxi- 

 mating 50 pounds for each one hundred 

 feet, or 300 pounds per square inch for a 

 depth of one hundred fathoms. 



The forms brought from the bottom on 

 the borders of the Gulf Stream, were so 

 varied and so different from those found 

 along shore or at moderate depths that, 

 until they had been seen repeatedly, they 

 caused the disturbing motions of the Fish 

 Hawk for the time to be forgotten. For 

 example, an annelid which lives in a tube 

 constructed from its own bodily secretions 

 early attracted my attention. The tube had 

 the appearance of quill; when burned it 

 gave the same odor as burning quill, and, 

 when cut into the shape of a pen, could be 

 used for writing the worm's name. An- 

 other was an interesting case of symbiosis, 

 or life-partnership, that had been made 

 familiar to those of us who had listened to 

 Professor Verrill's lectures. Here it was 



seen in the living condition, a hermit crab 

 having its home in a living house, that grew 

 as the crab grew, and consisting of a colony 

 of sea-anemones. Close examination would 

 usually show that the sea-anemones had 

 originally established themselves on the 

 shell of a mollusk in which the hermit crab 

 was living. The coenosarc common to the 

 anemone colony not only grew entirely over 

 the shell, but continued the lip of the shell 

 with enlarged gap so that the crab did not 

 need to seek a new and larger shell in sub- 

 sequent molts. Furthermore, the advan- 

 tage of this partnership is mutual. On the 

 one hand the crab is provided with a house 

 which adjusts itself to its needs and, with 

 its frieze of tentacles, armed with nettle- 

 like defensive organs, gives him a measure 

 of protection from his enemies. On the 

 other hand, the anemone is carried about 

 by its active partner and is thus afforded 

 a much more varied experience than it 

 would have if growing on a non-motile ob- 

 ject. Moreover, the crab, being a greedy 

 feeder, very unlike Chaucer's nun, who, 

 we are told, "let no morsels from her lippes 

 fall," allows many fragments of his meals 

 to float off in the surrounding water, is 

 thus, while eating, doubtless often encom- 

 passed by a cloud of crumbs which are as 

 manna to the colony of polyps which thus 

 become literally commensals or true table 

 companions. Such matters are, of course, 

 familiar to students and teachers of zool- 

 ogy, but may not be so familiar to those 

 whose biological training has proceeded 

 along different lines. An interesting fea- 

 ture about this case of commensalism is 

 that, while several hundred specimens were 

 collected in the expeditions of the Fish 

 Hawk to the Gulf Stream, these two species 

 were always found associated as commen- 

 sals. In other words, this particular species 

 of hermit crab was not found except as a 

 commensal of this particular species of sea- 



