Shaw . — The Seedling Structure of Araucaria Bidwillii. 333 
complicated series of fusions and divisions described, is a matter on which it 
is hardly safe to express an opinion. The fact that several of the indepen- 
dent strands seem to end blindly in the parenchyma suggests that there are 
some definite factors which operate in the rapid reduction in amount of the 
vascular tissue before it reaches the constricted zone. In fact the phe- 
nomenon is perhaps to be attributed to the indirect effect of an injury, or to 
the action of some unfavourable conditions under which the seedling grew. 
Summary. 
(1) The transition phenomena in Araucaria Bidwillii follow in broad 
outline the general method already described for other Gymnosperms. 
(2) The number of bundles entering the hypocotyl from the cotyledons 
is very numerous and variable. 
( 3 ) The number of protoxylem groups in the root structure at the base 
of the hypocotyl is also numerous and variable. 
(4) There is a reduction in the number of protoxylem groups in the 
younger parts of the root, diarch structure being finally attained. 
(5) The differences between the normal type of transition in Gymno- 
sperms and that in Araucaria Bidwillii are probably due to the tuberous 
nature of the latter, and are to be compared with those between the normal 
type of transition in Ranunculaceae and that in Eranthis. 
(6) A single specimen with abnormal external features showed 
aberrant internal anatomy producing numerous steles in the root. 
In conclusion, I desire to express my thanks to Professor Farmer, 
F.R.S., for his constant help and valuable advice throughout the progress of 
the research. 
Royal College of Science. 
February , 1909. 
Bibliography. 
1 . Borzi, A. : Biologia della germinazione dell’ Araucaria Bidwillii. Bot. Jahrb., ii, 1905, 
P- 2 73 * 
2 . Hill, T. G., and de Fraine, E. : On the Seedling Structure of Gymnosperms. Annals of 
Botany, vol. xxii, 1908. 
3 . Sargant, E. : Theory of the origin of Monocotyledons, founded on the structure of their 
Seedlings. Annals of Botany, vol. xvii, 1903. 
4 . Seward, A. C., and Ford, S. : The Araucarieae, Recent and Extinct. Phil. Trans. Roy. Soc., 
London, vol. cxcviii, ser. B, 1906. 
5 . Tansley, A. G. : Reduction in Descent. New Phytologist, vol. i, 1902. 
6. Worsdell, W. C. : Structure and origin of Cycadaceae. Annals of Botany, vol. xx, 1906. 
