30 A HALF-HOUR WITH THE 



and, the object being placed on the stage, a pencil 

 of light should be thrown upon it by the aid of the 

 bull's-eye condenser. If a seed of the redpo ppy 

 be now examined, it will be found to have a 

 uniform shape, and to be reticulated on its surface 

 (Fig. 127, PL 5). The seed of the black mustard 

 exhibits a surface apparently covered with a deli- 

 cate network (Fig. 128, PI. 5). Some seeds have 

 deep and curved furrows on their surfaces (Fig. 129, 

 PL 5). The great snapdragon has a seed covered 

 with irregular projecting ridges, having a granuled 

 appearance (Fig. 130, PL 5). The seed of the chick- 

 weed presents a series of blunt projections (Fig. 131, 

 PL 5). In the various forms of umbel-bearing 

 plants, the seeds adhere to the fruit, and the fruit 

 is commonly called the " seed." Such are caraway, 

 coriander, dill, and anise seeds. The plants of this 

 family are very common weeds in our gardens and 

 fields, and may be easily procured for microscopic 

 examination. Some of these fruits are covered 

 over with little hooks (Fig. 132, PL 5), whilst 

 others present variously-formed ridges and furrows, 

 which are amongst the best means for distinguish- 

 ing these plants the one from the other. 



