PRACTICAL WORK. NO. I. 201 



c. strands running from b towards d\ 



d. the nucleus, yellowish brown and very obvious ; 



e. the nucleolus; one or more nucleoli may be present. 



IV. Elodea. 



Mount in water a leaf of the common water-weed 

 Elodea. Examine a single cell with a high power and 

 note the circulation of the protoplasm. It may be 

 necessary to wait half-an-hour or so before circulation 

 begins. 



V. Tradescantia. 



Remove with needles a few hairs from the central 

 parts of the flower of Spider- wort (Tradescantia virginica 

 or other Tradescantia, e.g. T. fluminensis). Mount them 

 in water, taking care to prevent the coverslip crushing 

 them. Examine carefully with a high power, and note 

 the passage of minute particles along the strands from 

 the primordial utricle to the protoplasm surrounding 

 the nucleus : show the direction by small arrows on your 

 sketch. 



Should this circulation of protoplasm not take place at 

 once, slightly warming the slide as by holding it in your 

 hand may start it. 



