SENECIO VULGARIS. 243 



blem as to the reason of this remarkable provision. Probably the 

 fibres serve in securing the seed to the earth, when it has been 

 wafted thither by the agency of the wind. 



Another interesting fact in connection with the seeds is the 

 number of raphides and other crystals contained in the cuticle of 

 the unripened germ, and subsequently in the testa of the seed. 

 These, when mounted as a microscopic slide, present a very beau- 

 tiful appearance under polarised light. They are represented in 

 Plate 27, Figs. 4 and 5. 



The roots of Senecio vulgaris are very branching, of silvery 

 whiteness, and are densely covered with fine hairs. The large 

 number of branchlets and their hair-like appendages enable the 

 plant to take a firm hold upon the surrounding soil, and it is far 

 easier to break the plant short off from the earth than to draw it 

 out with the roots entire. The rootlet tip is well figured by Mr. 

 Lett in Plate XII., Fig. 7, of this volume.''^ 



The stem of Senecio vulgaris is irregularly cylindrical, having 

 very few hairs upon it ; it is sometimes of a reddish brown, 

 and sometimes of a uniform green colour. The more mature 

 stems are hollow, but in certain earlier stages they are filled with a 

 pith-like structure composed of pentagonal and hexagonal cells. 

 My own sections show internal cells larger than those figured by 

 Mr. Lett in Plate XII., Fig. 2 ; but he has very clearly shown 

 the fibro-vascular bundles. 



The leaves of this plant are winged, indented, alternate, and 

 clasping the stem ; they are sparingly covered with long, silky 

 hairs. The mid-rib is prominent, and forms a keel-like structure 

 at its union wdth the stem. The upper surface of the leaf is dark 

 green, and slightly rough, with many minute protuberances, and 

 the cuticle adheres so closely that it cannot be detached without 

 stripping away with it the dense masses of chlorophyll which fill 

 the internal portion of the leaf The underside of the leaf is of a 

 lighter shade, almost approaching to a greyish tint, and its cuticle 

 can be more readily detached. On this under cuticle the stomata 

 are numerous, but very minute, and although not readily distin- 

 guishable they may be well seen if the cuticle is stained and 

 examined with the spot-lens. Mr. Lett has given a faithful draw- 

 ing of this cuticle (PI. XIL, Fig. 6). 



* See "A Bit of Groundsel," p. loi. 



