Some Methods for Use in the Culture 
of Algae K 
BY 
H. MARSHALL WARD, D.Sc., F.R.S., 
Professor of Botany in the University of Cambridge. 
With Plate XXVIII. 
T HE following notes are somewhat of the nature of sug- 
gestions, since much has still to be done, no doubt, 
before the efficacy of the treatment and the faults and 
difficulties of the methods in detail are fully demonstrated ; but 
since the author has found they can be used with some measure 
of success, the various workers interested in the culture of Algae 
may care to take the methods up and try to improve them. 
i. If agar is swollen in dilute acetic acid, and then washed 
very thoroughly so that every trace of soluble salt is removed, 
it can be used, mixed with the necessary culture fluids, as 
a convenient medium for the growth of some Algae, as Bey- 
jerinck had already observed. But, so far as the author 
knows, the use of such a medium for separating Algae in plate 
culture and for observing their growth in hanging drops has 
not been attempted. It can be done, however, though the 
high melting-point of the agar and the sliminess of some 
Algae occasionally cause difficulties. 
The author has also succeeded in separating Algae by the 
following methods : — 
2. Shake them up in sterilized nutritive mineral solution, 
mix rapidly with silica jelly, also sterilized, and pour into 
1 Paper read before the Botanical Section of the British Association, at Dover, 
Sept. 1899. 
[Annals of Botany, Vol. XIII. No. LII. December, 1899.] 
P p 
