24 WEED-EATING 



down, defying all intrusion into liis privacy, there is 

 nothing very attractive in his person ; but when you 

 look at him crawling, especially through the side of a 

 glass vessel up which he is quietly mounting, you may 

 possibly find something to admire in his zebra-like 

 stripes and netted markings. I have more than once 

 heard the surprised exclamation, "Why, he is quite a 

 handsome creature !" But '' handsome is that hand- 

 some does ;" the Periwinkle is useful, especially to 

 those who mean to keep an Aquarium. The sea-water 

 constantly holds in suspension millions of the spores 

 (or seeds) of Algse, ready to adhere and grow as soon 

 as they find a resting-place, and these are particularly 

 abundant in the warm season. Whether those of the 

 green kinds, the CMorosperms — as the Ulva, Enter o- 

 morpTia, and various kinds of Confervce — be more 

 plentiful than others, or whether they are more easily 

 satisfied with a place congenial to their growth, I 

 know not ; but these grow most obviously, in the pro- 

 portion of a thousand to one. Before we have kept 

 our tank stocked a fortnight, its transparent sides 

 begin to be sensibly dimmed, and a green scurf is 

 seen covering them from the bottom to the water's 

 surface, which constantly accumulates, soon concealing 

 the contents of the vessel from distinct observation. 

 On examining this substance with a lens, we find it 

 composed of myriads of tiny plants, mostly consisting 

 of a single row of cells of a light green hue, forming 

 minute threads which increase in length at the ex- 

 tremity; others display small irregularly puckered 

 leaves of deeper green, which develop themselves into 

 Ulvce, or Enter omorphce. 



