CONTRIBUTIONS FROM THE ZOÓLOGICAL LABORATORY OF 
HE MUSEUM OF COMPARATIVE ZOÓLOGY AT HARVARD 
COLLEGE UNDER THE DIRECTION OF E. L. MARK. No. 124. 
SOME METHODS FOR USE IN THE STUDY OF 
INFUSORIA. 
A. W. PETERS. 
THE YARN SIPHON. 
IN accurate experimental work with Protozoa it often becomes 
desirable to separate them from the culture water in which they 
have grown and also from the solid débris, zoógloea, etc., con- 
tained in it. For one or several organisms this may be done 
by means of the “wash drop," as recommended by Eyferth 
(Einfachste Lebensformen, Braunschweig, 19 
To obtain clean specimens in larger dubbi the following 
method has proved efficient for many kinds of Infusoria. From 
the culture jar a quantity of liquid containing the organisms and 
the débris naturally occurring there is removed with a pipette 
to a Stender dish. In this the organisms are well distributed 
by sucking up the liquid into, and forcing it out of, the pipette 
a few times. This is occasionally repeated during the subse- 
quent procedure. A few pieces of woolen yarn about ro cm. 
long are then laid parallel in a single strand, held in water, and 
pressed together (not twisted) until thoroughly wet. This yarn 
siphon is then placed with one end in the Stender dish, now 
elevated, the other end hanging down on the outside, a receiving 
vessel being placed underneath. Soon ciliated organisms pass 
Over the siphon and are received into the lower vessel. The 
yarn acts as a filter as well as a siphon, keeping back solid 
matter and likewise dead organisms. From time to time fresh 
water is added to the Stender dish to replace that lost by 
siphoning. The process thus far yields the Infusoria in a large 
quantity of diluted culture water. 
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