SEEDS AND FRUITS 173 



is still attached to the single germi- 

 nated embryo. The other seed has not 

 shown any signs of growth. 

 h. Take a number of these fruits from which 

 one plantlet has sprung, and put them 

 in a pot and set out of doors for a 

 season. Many of them will be found 

 to germinate the second seed. 



c. Examine the young plant, and note the 



position and growth of the cotyledons. 

 What becomes of them? How does 

 the root develop? The single cotyle- 

 don of the species previously examined 

 did not come out of the seed-coats ; 

 what is the behavior in this instance ? 



d. Strip the seeds of several fruits, being 



careful not to injure them, and find 

 whether they will germinate alone. 



215. Nature of fruits of Xanthium. — The fruits 

 of Xanthium are seen to be adapted for the dis- 

 semination of the seeds by becoming fastened or 

 entangled in the coats of animals, and thus are 

 carried long distances from the parent plant. In 

 the case of migratory animals this method might 



