488 CHAPTER XXX IV. 



BKDOT recommends that this be done with strong solution of 

 Flemming, which should be added to the solution of sulphate 

 containing the Siphonophore, about two volumes of it being 

 taken for one of the sulphate solution. The whole should be 

 left for at least twenty-four hours. Lastly, a few drops of 

 25 per cent, alcohol should be added to the fluid with a 

 pipette, being dropped in as far as possible from the colony, 

 which should be disturbed as little as possible ; and further 

 alcohol, of gradually increasing strength, should be added so 

 gradually that the strength of 70 per cent, be not attained 

 under fifteen days at least. Ninety per cent, alcohol should 

 be used for definite preservation. 



I have tested this method. I do not find that the histo- 

 logical preservation is superior to that obtained by means of 

 the usual processes ; but the method is certainly a valuable 

 one in so far as it enables one to preserve specimens with all 

 their swimming-bells and polyps in situ, a result which is not 

 obtained by means of the usual methods. 



FRIEDLAENDER (Biol. Centrulbl., x, 1890, p. 483; Journ. Roy. 

 Hie. Soc., 1890, p. 804) preserves this class of objects by 

 inundating them with a mixture of 1 25 parts cupric sulphate, 

 125 parts zinc sulphate, and 1000 parts water. 



Lo BIANCO (he. cit., p. 454) employs for the majority of 

 Siphonophora a mixture of 10 c.c. of saturated solution of 

 corrosive sublimate with 100 c.c. of 10 per cent, solution of 

 copper sulphate. This is used as in BEDOT'S process. Diphyes, 

 Rhizopltysa, and Pkysalia, however, are killed with sublimate 

 solutions ; Velella with chrome-picric acid, or a mixture of 

 100 c.c. of sublimate solution with 50 c.c. of 1 per cent, 

 chromic acid ; Porpita by poisoning with liquid of Kleinen- 

 berg. 



KOKOTNEFF'S method of paralysing with chloroform has 

 been given in 15. I have seen Physophora very success- 

 fully killed by the careful administration of ether. 



Preservation, after fixation and washing, is greatly sim- 

 plified by the use of formaldehyde instead of alcohol 

 (WEBER). 



DAVIDOFF (Anat. Anz., xi, 1896, p. 505) fixes in formol. 

 He gets the animals, in sea water, into a large cylindrical 

 tube (test-tube), plugs its open end with cotton wool, and 

 stands it up, somewhat sloping, open end downwards, in a 



