Wall. — Distribution of Senecio saxifragoides Hook. f. 203 



(c.) They occur sometimes, not infrequently, near the margin, upon the 

 surface of the leaf, to a distance of about \ in. or -| in. from the 

 margin all round the leaf, as in Raoul's plate of S. lagopus. 



(d.) They occur most frequently upon small, ill-nourished, or depauper- 

 ated individuals. They occur more frequently upon the lower 

 and outer leaves than upon the upper and inner leaves. Leaves 

 bearing many bristles have been often found upon plants which 

 are in every other respect typical specimens of S. saxifragoides ; 

 some whole plants bearing such leaves have been preserved in the 

 collection mentioned below. 



The stout bristles may be almost certainly observed upon all 

 individual plants which are found growing alone, apart from the 

 large masses in which they generally cluster, such plants being 

 generally small and unfavourably situated as regards aspect or 

 soil. Many leaves of such plants have been preserved in the 

 collection, and in many cases the bristles are to be seen as thickly 

 congregated, as evenly distributed, and as stout as in typical 

 examples of S. lagopus and *S. bellidioides. Such leaves are, how- 

 ever, all small, much below the average size of the species, but 

 they are from undoubted examples of S. saxifragoides which are 

 seedlings from neighbouring masses of quite normal specimens. 

 A small plant of S. saxifragoides from Mount Pleasant, Port Hills, 

 which is now under cultivation at Canterbury College, has its 

 leaves thickly and evenly covered with the stout glandular hairs 

 here mentioned, and is in no respect to be distinguished from 

 specimens of S. lagopus of the same age. (See Plate XIII.) 



9. Microscopical examination of the so-called bristle yielded the follow- 

 ing results : — 



(a.) The bristles are simply typical glandular hairs. 



(b.) The bristles have exactly the same structure in both species. 



(c.) The bristles upon the margin of each species differ from those of 

 the blade only in the length of the stalk, except that in the case 

 of S. saxifragoides there is a slight difference in colour. 



(d.) The " silky hairs " of both species have exactly the same structure. 

 The " hair " arises from a single cell, the " bristle " from several. 



(e.)The glandular organ on the margins of the leaves is a typical hyda- 

 thode. 



(/.) The variegated appearance of the bristle is due to the arrangement 

 of the colouring-matter, which is present in some cells, absent in 

 others, with no definite arrangement. 



3. Distribution on Banks Peninsula. 



For the purpose of this study the forms of Senecio lagopus were observed 

 on all the chief peaks on both sides of Akaroa Harbour, such as Brasenose, 

 Stony Bay Peak, Mount Bossu, and Carew Peak ; then on the principal 

 high points on the ridge connecting the Akaroa Harbour heights with the 

 main mass of Mount Herbert, such as Mount Sinclair and Mount Fitz- 

 gerald. These points are all between about 2,500 ft. and 2,700 ft. high. 

 Both peaks of Mount Herbert, 3,000 ft. and 2,800 ft. respectively, were 

 visited on several occasions. Specimen leaves of S. lagopus were collected 

 from various points, especially from Mount Herbert, and preserved. 



The forms of Senecio saxifragoides were next observed, and found to 

 occur on all the peaks of the Port Hills from that south-west of Cooper's 



