TUK BOTANY OF THE FARM. 435 



The morphological characters of the plants undvTgo a change. In gen- 

 eral terms, it may be said that the growth of the stein is arrested, and 

 tin- growth and mode of development of the leaves not only n\ but 



more or less profoundly modified, so as to form the parts of the flower. All 



of the flower are constructed on the same original plan as lea 



The process of fertilisation mav h described in general terms as fol- 



'8 : The ovule contains, in a cell just beneath the skin at its summit 



special piece of protoplasm, the "germ/' which is destined to develop 



the embryo plant. The pollen-cell consists of an outer coat and an 



inner lining ; the outer coat bursts, and the inner protoplasmic lining is- 



protruded in the form of a tube, which passes down between the cells- 



of tin- ^tignia and style, growing in length and feeding as it goes, like a, 



.sitic fungus, on the contents of the cells of the style, till it reaches 



ovule and comes in close proximity to, if not actually into contact 



with the germ. In consequence of this action a cell-wall is formed around 



th- L, r erm, which latter divides and subdivides in various directions, the 



ilt of the Mil. division being the formation of an embryo plant, while 



ovule covering the embryo ripens into the seed. The germ is thus 



the pollen or sperm-cell, and unless the two come in contact, 



the formation of the embryo plant does not take place. 



!'K UTILISATION. It has been mentioned that the flowers with 



whieh the larm--r is concerned have for the most part their stamens and 



pi-ti!< in the same flower (hops are an exception), and therefore they may 



be described as structually hermaphrodite. It does not, however, follow 



v are functionally hermaphrodite that is, that the pollen-grain 



ny particular flower fertilises the germ-cell of the same flower. As a 



Dually happens, and the pollen of one flower 



bs influence, not upon the germ of its own flower, but upon that 



>p^ situated on some other plant. Cross-fertilisation U 



1 by the circumstance, that while the pollen of any p 



,!ar flower may be ri; ;--ma and the germ-cell of the same flower 



!.' rip.- at the saint- tim- slid in such case the CO- 



other flower is ne.-d (!. 



HYMKMHSATIMN is a pme.-duiv with which the gardener is much more 

 famili ir than tin- farm, r It is only a further development of . t ili- 



Cross-fertilisation, as has b. t ikes place between flo\s 



aim- individual plant, or between flowers of t \\ dilleivnt indi 

 i. ut hybridisation is effecteorby crossing the 

 of two separate spec n the case of AJlike elover, which ifl 



hybrid ' the white or hutch clover and tin red el> 



