Published online by Cambridge University Press: 31 May 2012
Freeze-drying has become widely accepted as a means of concentrating and preserving substances without destroying biological activity, and is becoming increasingly important in various entomological and bacteriological studies. The methods and tvpes of apparatus used have been recently reviewed by Harris (1954). The apparatus described in this paper was developed at the Entomology Laboratory, Ottawa, for drying small quantities of insect tissue. It is sturdy and may be easily and cheaply constructed from readily available laboratory supplies with common machine-shop tools.