Growing Gladophora in the Laboratory 



I. C. G. Cooper 



After several abortive attempts to keep Cladophora alive in the 

 laboratory, the writer has used the apparatus shown in Figure 1 

 with success. 



C. glomcrata (L.) Kiitzing is a plant of well aerated waters, 

 in fact the specimens used were gathered from rocks below a weir 

 where they were constantly splashed. The device was conceived 

 with the idea of furnishing aeration and possibly some motion in 

 the fluid. 



The contrivance is simple to construct and operate. On a shelf 

 about 27" above the laboratory table is placed a one-gallon bottle 

 (A) with a siphon tube of ;^4" o.d. rubber (B) which has its outer 

 end steadied by passing it through a Y^q" hole in the wooden 

 support (C), and which is in turn secured by the clamp (D) to 

 the edge of the shelf. Immediately beneath the siphon tube a Yiq" 

 hole in the shelf forms a support for the thistle tube (F). To the 

 lower end of the thistle tube a glass "tee" (G) is attached by a 

 2" length of rubber tube (H). The stand (S) is made of wooden 

 battens %" x 1^" and is 10" high with top batten about 7" long, 

 having two ^e" holes-about 5" apart through which are passed the 

 rubber tube (J) attached to the lower end of the "tee" and the glass 

 tube (M) which is joined to the branch of the "tee" by the rubber 

 tube (L). The tube (J) is led to the bottom of a 16 oz. flask (K) 

 which is stood in a beaker (T). The glass tube (M) extends to 

 the bottom of the 250 c.c. flask (N). 



The end of the siphon tube (B) is plugged with a conical plug 

 at E. Details of this plug are shown at E'. The plug in use is made 

 of maple and is 1" long and a little less than ^4" diameter at the 

 thick end. That end is cut flat and with fairly sharp edges. Grooves 

 are cut in the sides as shown. These grooves do not extend closer 

 to the thick end than 54"- 



To start operations, fill bottle A seven-eighths full and flask K 

 completely with w^ater and place about 200 c.c. of nutrient fluid 

 in flask N. Set the siphon going and adjust the plug E until the 

 speed of dripping is about three drops in five seconds. Now arrange 

 the support C so that the drops fall directly into the throat of the 

 thistle tube. 



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