Scientific Intelligence, — Zoology. 211 



which I have recently made, and which I purpose to publish 

 elsewhere in all their details, have clearly demonstrated, that 

 the various colours, rose, orange, blood-red, and reddish -brown 

 (varieties owing to more advanced growth), which are inclosed 

 in, or which surround, the translucid and colourless structure 

 of different kinds of agates, were found to be owing to the pre- 

 sence either of red globules uniformly mixed, as in the carne- 

 lian agate ; or agglomerated into small irregular clots, and dis- 

 tributed into circular waves, according to certain forms or con- 

 ditions which existed at the time of the siliceous conglomera- 

 tion ; or finally, though more rarely, to these small red vegeta- 

 bles themselves, quite entire, and perfectly distinctly visible 

 with the microscope. It is impossible to find a resemblance in 

 colour and polish more strikiug than that which is seen in a 

 white glass phial filled with Protococcus kermesinus, when com- 

 pared with a carnelian, as may be fully established by the triaL 

 (M. Turpin.) 



15. On the Stinging Power possessed by some Mediisce, — It 

 appears that the belief in the stinging or burning power of the 

 Medusa aurita is founded on a confusion of species. In the 

 East or Baltic Sea, where this species alone is found, I|have often, 

 while bathing, brought my body in contact with the animal, 

 without receiving any injury. Even touching it with the 

 tongue caused no feeling of sharpness. On the contrary, I have 

 suffered much in the North Sea, from violent burning and gell- 

 ing of the back of the hands, caused by much contact of the hand 

 with the red Cyanea {^Medusa) capillata. In the North Sea, there- 

 fore, as at Wangeroge, Norderney, Heligoland, Cuxhaven, &c., 

 bathers ought, as in the Mediterranean Sea and the Atlantic, to 

 avoid contact with medusa? ; while on the south coasts of the 

 Baltic, as at Swinemiinde, Doberan, &c., they have nothing to 

 dread from these exquisitely beautiful creatures. It is, therefore, 

 undoubtedly proper to warn bathers in other places than the 

 Baltic, against coming in contact with any medusae whatever, aS 

 it is an easy matter to confound the injurious with the harmless 

 species. Even on the northern coasts of the Baltic, injurious 

 medusa? are frequently to be met with after storms. They 

 sj)eedily die, however, is they require Salter water ; so that on 



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