A Consideration of the Facts relating to the 
Structure of Seedlings. 
BY 
T. G. HILL 
AND 
E. de FRAINE. 
With a Curve, two Diagrams and one Figure in Text. 
HE consideration of the facts relating to the structure of seedlings 
JL leads to interpretations and conclusions which differ according to the 
habit of mind of the investigator ; it is not proposed to enter into all 
of these here, but merely to give expression to some ideas which are the 
outcome of our work on this subject . 1 
At the present day anatomical investigations in the main are carried 
out from the point of view either of phylogeny or of physiology, and 
the subject of seedling anatomy may conveniently be considered from these 
two aspects. 
Phylogeny. 
For the purposes of argument, it may be assumed that the cotyledons 
are really the same thing as foliage leaves — and this is our opinion — 
although modified to perform special functions ; if they be organs sui generis , 
as is sometimes supposed, then much, if not all, of the interest attaching to 
them from the point of view of phylogeny disappears. 
The examination of a large number of plants will generally lead to the 
possibility of arranging them in a series with the most complex and 
the most simple situated on either flank. The difficulty arises in deciding 
which of the two extremes is primitive, and here there seems to be a some- 
1 Hill, T. G. : On the Seedling-structure of certain Piperales. Ann. Bot., xx, 1906. Hill, 
T. G., and de Fraine, E. : On the Seedling-structure of Gymnosperms, Pt. I. Ann. Bot.,xxii, 1908 ; 
Pt. II, id., xxiii, 1909; Pt. Ill, id., xxiii, 1909; Pt. IV, id., xxiv, 1910. de Fraine, E. : The 
Seedling-structure of certain Cactaceae. Ann. Bot., xxiv, 1910. Hill, T. G., and de Fraine, E. : 
On the Seedling-structure of certain Centrospermae. Ann. Bot., xxvi, 1912. Hill, T. G., and 
de Fraine, E. : On the Influence of the Structure of the Adult Plant upon the Seedling. New Phyt., 
xi, 1912. 
[Annals of Botany, Vol. XXVII. No. CVI. April, 1913.] 
