112 METHODS OF COLLECTING AND PRESERVING 
Hydrocorallince. —This group includes the Milleporidce and 
Sty luster idee. Any observations on the living polyps would be 
valuable. It would be of special interest to discover the minute 
medusiform individuals which escape by rupture of the wartlike 
elevations which stud the surface in certain parts. 
Moseley’s method of sudden killing of specimens with expanded 
polyps by means of hot corrosive sublimate should be tried. 
Siphonojjhora. —These animals are very difficult to preserve satis¬ 
factorily, owing to the tendency of the swimming bells, polyps, and 
tentacles to break away. The method of killing and fixing with 
osmic acid, washing in fresh-water, and grading into alcohol, 
may be adopted (see below, Medusa 1 ). For other means of 
preserving, the collector is referred to Signor Lo Bianco’s paper 
on the Naples methods, or to the cupric-sulphate method of Bedot, 
quoted by Mr. A. B. Lee.* 
Medusce. —Medusae in many instances represent merely one phase in 
a series of transformations undergone by an organism in the course 
of its life-history. 
Many of the smaller forms are budded off from fixed Hydroids. 
In the case of some of the larger forms (e.g. Aurelia) the oval free- 
swimming embryo settles down and becomes a minute white polyp 
with long tentacles; the polyp divides transversely so as to resemble 
a pile of saucers; the latter become free, and ultimately develop into 
the adult form. It is important to obtain all these stages. 
The discovery of new forms of fresh-water Medusae would be an 
event of the greatest interest. 
Recently Mr. E. T. Browne f has obtained good results in pre¬ 
serving the smaller kinds of Medusae by using formalin, after killing 
and fixing with a saturated solution of picric acid. The contents of 
the towing-net are emptied into a glass vessel of sea-water. By 
means of a pipette any particular specimen is removed to a watch- 
glass of sea-water. Five drops of hydrochlorate of cocaine are 
added, and in a few minutes another five or ten drops. When 
the Medusa is motionless and has its tentacles extended, any 
* “ Microtomist’s Vade Mecnm,” 5th edit., 1900, p. 487. 
f E. T. Browne, “ Proc. Liverpool Biol. Soc.,” 1895, IX., p. 245 ; “ Proc. Zool. 
Soc.,” 1896, p. 461; and “ Journal of Bioxnetrika,” 1901, Vol. I., p. 108. 
