254 THE NOCTILUCA. 



window between my eye and the light, and was not 

 long in discovering, without the aid of a lens, a 

 goodly number of the tiny globules swimming about 

 in various directions. They swam with an even glid- 

 ing motion, much resembling that of the Volvox 

 glohator of our fresh water pools, but without any 

 revolution that I could perceive. They appeared 

 social, congregating into little groups, of half a dozen 

 or more together ; and when at rest affected the sur- 

 face and the side of the glass next ■ the light. A 

 jar or shake of the vessel sent them down from the 

 surface. 



It was not very easy to catch sight of them, nor to 

 keep them in view when seen, owing rather to their 

 extreme delicacy and colourless transparency than to 

 their minuteness. They were in fact distinctly appre- 

 ciable by the naked eye, for they measured from — th 

 to -^ th of an inch in diameter. 



With a power of 220, each was seen to be a globose 

 sac of gelatinous substance, ordinarily smooth and 

 distended, but occasionally roughened with fine 

 wrinklings in the surface. At one side there is a 

 sort of infolding, exactly like that of a peach or plum 

 (see figs. G and 8, Plate XVI.) ; and this if viewed 

 directly sidewise appears to be a deep furrow, from 

 which the two rounded sides recede, with two minor 

 lobes between them. (See fig. 7). From the bottom 

 of the furrow springs a small slender proboscis of a 

 thickened ribbon-form, very narrow, and about as 

 long as two-thirds the diameter of the globe, with the 

 tip slightly swollen. (Fig. 11). It is frequently 

 twisted with one curl, but is moved sluggishly in 



