746 



THE HYDRAS. 



These symptoms last for ten or twelve hours before they fairly abate, and even after 

 several days the very contact of the clothes is painful to the skin. The shooting pangs 

 just mentioned are of longer duration, and I have felt them more than three months 

 after the Cyanaea had stung me. 



To the unaided eye the filaments which work such dread misery are most innocuous 

 and feeble, being scarcely stronger than the gossamer floating in the air, and looking 

 much as if the Medusa had broken away a spider's web, and were trailing the long 

 threads behind it. The microscope however, reveals a wondrous structure, which, 

 though it cannot precisely compensate for the sufferings inflicted by these tentacles, 

 can at all events endow them with an interest which would not otherwise be felt. 



Lest any of my readers should become fellow-sufferers with myself. I advise them 

 to be very careful when bathing after a strong south-west wind has prevailed, and if 



Khlzostoma Cuvlert. 

 Cyansea capillata. 



Medusa aurit*. 



ever they see a tawny mass of membranes and fibres floating along, to retreat at once, 

 and wait until it is at least a hundred yards away. Some may suppose that this 

 advice is needlessly timid, but those who have once felt a single poison thread across 

 their hand or foot will recognize that discretion is by far the wisest part to be played 

 whenever there is the least danger of being stung by the Cyanaea. 



THE last family, of which the large upper figure affords an example, is easily known 

 by the absence of a mouth. In the typical genus, Rhizostoma, the footstalk is deeply 

 scooped into semi-lunar orifices, and the eight cartilaginous arms are without fringes. 

 This beautiful genus is also seen on our coasts. 



BEFORE taking a final leave of these remarkable beings, it is needful that we should 

 briefly notice the strange metamorphosis through which some of them pass before they 



