MAIZE GERMINATION 133 



(c] It will be found useful to compare the germination of 

 other seeds also, e.g. the Broad Bean, Kidney Bean, Cucumber 

 or Gourd, &c. 



(B) Monocotyledons. 



I. Comparing plants of Maize which have been germinating 

 for different periods, the following facts in the history of ger- 

 mination may be observed : 



1. The fruit swells. 



2. The outer coat ruptures opposite the apex of the radicle, 

 which soon protrudes, bursting through the coleorhiza also, 

 which appears as an irregular ring round the base of the young 

 root. Since the coleorhiza is thus burst through by the young 

 root, it is clear that the epidermis of the shoot is not continuous 

 with the piliferous layer of the root. 



3. The rupture of the coat extends upwards to the point 

 opposite the apical bud, which also emerges. 



4. The root elongates, and forms lateral roots : other lateral 

 roots (usually two) burst out above the insertion of the scutel- 

 lum : these soon equal the primary root in length, hence there 

 is no well marked tap-root. 



5. Leaves of the plumule unfold, and gradually turn green : 

 the leaf inserted lowest, which was the outermost of those 

 composing the plumule, remains small and develops no ex- 

 panded lamina : this is the cotyledon, according to Hofmeister 

 and other writers. 



II. From a young plant with leaves about three inches 

 long, cut longitudinal sections so as to traverse the whole 

 fruit and the contiguous part of the seedling in a median 

 plane : mount in water, and irrigate with solution of iodine 

 Observe 



1. That in the neighbourhood of the surface of the scutellum 

 the starch-grains are in course of demolition, and that the 

 central part of each is first attacked. 



2. That no starch-grains are to be seen in the epithelium of 

 the scutellum. 



