FLOTSAM AND JETSAM 203 



still has the gland which secretes this, but has 

 etherealized its use. The thin secretion is poured 

 forth, and then, by successive upreachings of a 

 part of the foot, bubbles of air are caught and en- 

 tangled in the slime, which soon extends out as a 

 narrow buoyant raft, the shell hanging down at 

 one end. The bubble slime is not only balloon but 

 nursery, and egg after egg is suspended from the 

 lower surface. So abundant were these snails that 

 I observed them with only general interest, think- 

 ing of course that their whole life history was 

 well known, but on my return I found that this was 

 far from the case, and that few facts are known 

 about them. 



There are two kinds of thrills in science; one 

 is the result of long, patient, intellectual study. 

 An example of this is the years of astronomical 

 calculation whereby movements of certain heavenly 

 bodies can be explained only by the existence of 

 some unknown factor, and then one day this un- 

 known but expected star is found at the very spot 

 indicated by mathematical necessity. 



Another thrill lies in an absolutely unexpected 

 discovery. Night after night small white spots 

 floated about on the water just beyond the glare 

 of the gangway electric lights. In vain we tried 

 to net them. Now and then several would join 

 together in a sinuous row and swim slowly along. 

 At last, with an effort which almost precipitated 

 him into the sea, Serge Chetyrkin scooped one up 

 and dropped it into a small jar. To my astonish- 

 ment I saw it was an argonaut or nautilus — a 



