MATERIAL AND METHODS 305 



be drawn out from the float for sampling in the same way without loss, though it is better to cut out 

 the complete air-sac. 



The pneumatocyst can be quickly removed from a living specimen by making an incision with 

 scissors down the wall of the pneumatocodon, while it is held by the crest in the air. Contraction of 

 the outer muscular wall soon frees the sac, which can be tied off for safety short of the aboral valve before 

 cutting off the remains of the pneumatocodon. Pressure can then be applied to the immersed sac 

 (which of course floats) to dilate the dorsal processes until fixation is complete. 



Physalia, it was found, could be handled by the float without fear of stinging, but a pair of plastic 

 salad-servers, kept scrupulously clean, was used for handling the numerous laboratory specimens, 

 and particularly for lifting them in a breeze from the sea into buckets. In this operation it was found 

 imperative to avoid allowing the tentacles to touch either oars, gunwale or thwarts of the boat; 

 tentacles adhere tightly to wooden objects and are almost impossible to remove. When lifted from the 

 sea the tentacles may hang down for 5 or 6 ft. and need careful handling in a breeze. 



The authorities at the Victoria Hospital at Las Palmas, where hundreds of stung patients are 

 treated, advised the taking of an anti-histamine if badly stung, but there was no occasion to do so 

 because the precautions outlined above were taken. 



From my rough diary I see that specimens of Physalia were available at Arrecife, where we arrived 

 on 18 February 1955, as follows: 



4 March First specimens brought in by Senor Don Jorge from Graciosa I. 

 10 Three right-handed specimens drifted in. 



15 Wind S.E. all day, but dropping. At 5 p.m. numerous left-handed Physalia taken. Later when wind was 



S.W., many right-handed specimens taken. 



20 Calculated that with present wind Physalia would pass 1 or 2 km. south of Arrecife, where in fact none 



came ashore. Drove to Caletta on north coast and picked up thirty-two. 



4 April Many young specimens drifted on to beach on east side of Islote de Ids Ingleses. 



9 One specimen, 4-5 in. float-length. 



13 Strong N.E. trades. Many left-handed Physalia. First experiments on drifting. 



15 A few Physalia. Second set of drifting experiments. 



16 Sixty-five specimens brought in by boys. Third set of drifting experiments. 

 18 One young specimen. 



21 A large sea-area covered by specimens, spotted through binoculars at 6.30 p.m. half-a-mile south of 



laboratory. Two dozen brought in. 



6 May One young specimen from east side of Islote. 



10 One young specimen. 



12 Small specimens. 



13 Three small specimens. 

 24 Departure. 



I could get no reliable information in the Canaries as to periodicity of appearance of Physalia, 

 except that at Las Palmas they were most noticeable up to June, after which they decreased in 

 numbers. There was a common belief that they bred on a reef protecting El Canteras beach on the 

 north side, and were washed off the reef into the bathing-area. 



The Arrecife boys soon came to know that we were interested in ' agua viva ' as they called Physalia, 

 and I used to issue buckets and a pair of plastic salad-servers to the best collectors, with a warning 

 that only really fresh specimens, and particularly very tiny ones were needed. If specimens are to be 

 kept in good condition for more than a day or so, very large vessels are required, such as the hatching- 

 tanks used by Brooks and Conklin (1891). 



