METHODS OF USING CULTURE MEDIA 



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A. "Vignal tubes" of the style shown (Fig. 123) are made 

 from glass -tubes of about 6 to 8 mm. outside diameter, 



Fig. 121. — Tank with raised lids. (Vaughan.) 



Fig. 122. — Tank with lids lowered. (Vaughan.) 

 Figs. 121 and 122. — Vaughan and Novy's mass culture apparatus. 



