XIX.] 



CLOVER DODDER. 



119 



leaves are represented by one or two very minute scales 

 in germinating dodder. 



Clover and dodder seeds, farther advanced in growth, 

 are shown at Fig. 50, twice the size of nature. The clover 

 seeds on the left are sending their first roots deep into the 

 earth, whereas the dodder seeds on the right are sending their 

 threads into the air in search of a host on which to live 

 parasitically. The ground line is indicated at A. Clover 

 and dodder seeds generally germinate after the lapse of a 

 week or less ; but certain seeds of clover dodder from the 



X 2 



FIG. 50. 



Clover and Dodder seeds germinating. 

 Twice the size of nature. 



sample we experimented with did not germinate till two 

 months had passed. The variation in the time of rest in and 

 on the ground before germination is an obvious advantage to 

 the dodder, for, if the first dodder seedlings find no hosts 

 ready for them, other seedling dodders, during a period 

 of two months, still have a good chance. Clover often 

 remains without producing other than the two first seed 

 leaves for one or two weeks, and during that period the 

 young dodders often attach themselves to the clover seed- 

 lings, as illustrated at Fig. 51, enlarged ten diameters. 



