1 62 Elementary Biology. 



Each stamen consists of a petiole, or filament, and a 

 club-shaped head, the anther (fig. 81). The anther itself 

 consists of a centrally placed continuation of the filament 

 known as the connective, which is, however, nothing more 

 nor less than the midrib of the sporophyll, and four elong- 

 ated bodies, two on either side of the midrib, all of them 

 pointing towards the centre 6f the flower (introrse). These 

 bodies are the sporangia which are sessile in the great 

 majority of angiosperms. The sporangia are therefore, in 

 the lily, developed not in the axilla, but on the edge of the 

 sporophyll, towards its upper surface. The spermospores 

 fill the interior, or loculus, of the sporangium, and are 

 known when ripe as pollen grains. 



Passing now to the central sporophylla, or carpels, we 

 find that, in addition to still further modifications in form 

 the three carpels have become united to form one mass 

 known as the ovary, which is in this case described as 

 compound (fig. 79). If a section be made across the 

 ovary the three separate chambers which are then exposed 

 demonstrate its compound nature. In each cavity we ob- 

 serve the sporangia, here known as ovules. The spo- 

 rangia are stalked, are numerous, and are arranged in six 

 rows, two rows in each chamber. 



The ovary is continued upwards as the style, and ends 

 in a bulb-like furrowed head, the stigma (fig. 79). The 

 style, on a transverse section being made, is found to be 

 hollow, and the stigma, if microscopically examined, is seen 

 to be covered by a number of short hairs. 



On what part of the sporophyll are the sporangia borne ? 

 A careful study of the development of the carpel shows us 

 that the sporangia are really developed, as in the case of 

 the male sporophylla, from the edge of the carpellary leaf. 

 The edges are, however, during development turned inwards 

 upon themselves, and ultimately unite so as to form a cavity, 

 with, consequently, the upper surface of the carpellary leaf in 

 the interior (fig. 83). The sporangia are thus completely en- 



