Ch. XXI.] THE TOWING-NET. 355 



in which every possible condition favoiirable to floating and 

 delicate animals seemed to be fulfilled ; yet not a visible 

 speck broke the mirror-like smoothness of the blue sea from 

 morning till night, excepting only the shoals of flying-fish, 

 which from time to time reheved the somewhat monotonous 

 scene with the life of motion. 



Floating animals, then, are of such a character as to be 

 either visible or invisible from the point of observation. 

 The iavisible ones are so miuute, or so transparent, that 

 they can only be recognized when taken in the towing-net 

 — a bag of muslin or bunting with wide mouth, and which 

 being let over the side of the vessel, skims the surface of 

 the sea. The contents, indeed, are not unfrequently so 

 delicate, that even when thus captured, and placed in a 

 vessel of sea-water, they can only be perceived when held 

 in a favourable light, or followed by means of some speck 

 of colour which distinguishes them as they move along. 

 The small Gymnophthalmatous Medusidse (naked-eyed Me- 

 dusae) are of this kind, and may be very abundant, but 

 would otherwise pass unnoticed ; and it is seldom that the 

 net is put down without securing various beautiful forms 

 of such transparent Medusae, as weU as Beroes, &c., and 

 small gelatinous masses, usually more or less torn by con- 

 tact with the net. Many minute bodies doubtless pass 

 through even the finest meshes ; and it is evident that 

 the net can only be used to advantage when the weather 

 is fine, the sea tolerably calm, and the ship not sailing 

 too fast. 



I have never found the net entirely empty, excepting on 

 one or two occasions, in the Singapore Straits ; for although 

 the nature and variety of its contents varied much, it most 

 usually contained a great deal that was interesting and 



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