108 
Variation in A^trelia Aurita 
Method used for the Preservation of Aurelia. 
The large adults were placed in buckets containing Formaline 5 p.c. solution 
in sea-water. (Formaldehj'de 5 c.c. and sea-water 95 c.c.) They quickly died in 
a good state of expansion. When the bucket was full of specimens about 100 c.c. 
of strong Formaldeliyde was added. The specimens were allowed to soak in this for 
six hours and occasionally stiired up. After this preliminary soaking in Formaline 
they were removed, one by one, and placed in a mixture of Formaline and Chromic 
Acid. 
Formaline, 10 p.c. in freshwater 9 volumes. 
Chromic Acid, 5 p.c. solution 1 volume. 
They were left in this mixture for 24 hours ; occasionally stirred up and a 
little strong Formaldehyde added. It is very important that the specimens should 
be thoroughly saturated with Formaline. The specimens were removed from the 
Chromic-Formaline solution and finally stored in bottles containing Formaline 
10 p.c. in freshwater. I pi'efer storing in a 10 p.c. solution of Formaline, as there 
is then a fair margin against deterioration of strength. 
These specimens are now three years old and are still in excellent condition. 
The addition of Chromic Acid greatly improves the specimens. The opaque 
whiteness, produced when Formaline only is used, is not so conspicuous and the 
jelly becomes more translucent. The specimens are also tougher and more pliable 
and can be handled without fear of damage. The yellowish-brown colour due to 
the Chromic Acid gradually disappears owing to oxidation and the specimens turn 
to a pale bluish-green. An ordinary black xylonite photographic dish is an 
excellent thing to examine the specimens in. The black background shows up 
the radial canal system. 
References. 
Ballowitz, E., 1899. "Ueber Hypomerie und Hypermerie bei Aurelia aurita." 
Archiv fur Entivickehmgsmechanik der Organismen, Bd. vill. pp. 239 — 252. 
(This paper contains a good Bibliography and summary of the literatui'e 
relating to the variation of Aurelia.) 
Browne, E. T., 1895. " On the Variation of the Tentaculocysts of Aurelia 
aurita." Quart. Joiirn. Micro. Sci., Vol. xxxvii. pp. 245 — 251. 
