2 ON SEEDLINGS 



radicle, or both may be comparatively stout and of equal 

 length. 



Seedlings. Where the seed is minute the seedling must 

 also necessarily be small, but the outline of the cotyledons 

 depends greatly upon the presence or absence of endosperm. 

 The latter has also a great influence upon the size of the 

 seedling both during and after germination. As endosperm 

 is generally absent the seedlings are minute and of slow 

 growth in the early stages. The cotyledons of Begonia villosa 

 (fig. 392) are roundly elliptic, entire, shortly petiolate, and 

 close to the ground owing to the shortness of the hypocotyl. 

 The first leaf is cordate, entire, and the second reniform- 

 orbicular and crenate, followed by others which are gradually 

 larger, broader and more or less oblique, the latter character 

 being very prevalent in the Order. The seedlings of B. parvi- 

 flora, B. boliviensis, B. Veitchii, B. Pearcei and other tuber- 

 ous species agree pretty closely in general characters with the 

 above. The cotyledons of B. modesta (fig. 393) are small, 

 oval, shortly petiolate and both directed to one side of the 

 axis. The first leaf is subreniform, entire and oblique, fol- 

 lowed by a second that is larger, serrate at the base and very 

 oblique. The third is still more oblique and irregularly den- 

 tate. The behaviour of the cotyledons is apparently due to 

 their being connate by their petioles at the base. 



Begonia villosa, Lindl (fig. 892). 



Primary root slender, with comparatively strong adventitious 

 lateral roots near the upper end at a very early stage. 



Hypocotyl very short or undeveloped, or suddenly tapered to a 

 blunt point and giving off adventitious roots. 



Cotyledons very small, rotund, obtuse, very shortly petiolate, 

 glabrous, light green, with a slender midrib but no other discernible 

 venation; lamina 1-1-25 mm. in diameter; petiole dilated and 

 slightly connate at the base, about -5 mm. long above the connate 

 part. 



Stem herbaceous, erect, terete, slightly pubescent; primary 

 internodes undeveloped. 



Leaves simple, radical and cauline, alternate, stipulate, petiolate, 

 more or less pilose on both surfaces when young, with jointed 

 hairs, unequal- sided, with alternate, ascending or incurved nerves, all 



