4 MR. К, H. COMPTON: AN INVESTIGATION OF THE 
abundant in the Leguminose, recourse was had to piercing the testa or 
treating the seeds with strong sulphuric acid before sowing. 
The seedlings were uprooted when sufficiently grown; the standard age in 
the case of most epigeal species is the end of the first phase of growth, when 
the cotyledons are fully expanded and the plumule is as yet undeveloped. In 
many cases, however, the plumule develops so early that the first and second 
phases of growth overlap : and it is obvious that the criteria used for epigeal 
do not apply to hypogeal species. Therefore no constant standard founded 
on external appearance can be used throughout the Leguminose. Uniformity 
‘can, however, be attained anatomically by describing primary vascular 
structures at their full development, though it frequently happens that 
cambial activity begins before the primary structure is fully differentiated. 
The seedlings were preserved, some in 70 per cent. aleohol and some in: 
Carnoy's fixing fluid (transferring to spirit) ; but the best method for the 
present purpose was found to be simply immersion in methylated spirits, and 
this was adopted in the majority of cases. 
The strueture was investigated by means of transverse (and occasionally 
longitudinal) sections. In the case of the largest seedlings these were cut by 
hand, but in most cases the material was embedded in paraffin and micro- 
tome series were prepared. 
The sections were double-stained : the best results with the microtome 
sections were obtained by the use of Methyl Violet in 50 per cent. alcohol, 
followed by a solution of Erythrosin in elove-oil. Тһе seetions were cleared 
in clove-oil and mounted permanently in Canada balsam. For the hand- 
sections Methyl Violet followed by Bismarck Brown was found to give highly 
satisfactory results. In a few cases sections were mounted in glycerine or 
Schultz’s Solution: and for quick examination a one-solution mixture of 
Methyl Violet and Licht Grün was occasionally useful. 
The work has been carried out at the Cambridge University Botany School, 
where I have enjoyed the facilities kindly placed at my disposal by Professor 
A. C. Seward. 
The descriptions which follow were, in the majority of cases, prepared from 
an examination of several seedlings of each species. In a few instances a 
single specimen alone was examined, but where there is reason to think that 
this is not typical a note is inserted to that effect. It is probable that in some 
variable species, e. g. Voandzeia subterranea, Vicia Faba, examination of 
further specimens will supplement the account here given. In by far the 
greatest number of species, however, the mode of transition and the structure 
generally have proved extremely constant. 
For the most part the transition is described, beginning at the primary 
root and ascending to the cotyledons. The reverse mode of description has, 
however, been taken into consideration, and is used for convenience in a few 
special instances. 
