5 1 o Worsdell . — The Morphology of the Monocotyledonous 
As the above would seem to be an uncommon abnormality, it seems 
desirable to indicate what, in my opinion, is its probable meaning. This 
involves a brief discussion of the much-debated morphology of the different 
parts of the Grass-embryo, as also of the Monocotyledonous embryo in 
general. Every one is familiar with the structure of the Grass-embryo, so 
it need not here be described in detail. 
I will merely take each of the main parts 
in turn and give a brief historical account 
(a complete one is unnecessary, having 
been given by previous writers) of the 
views held as to their nature. 
Nature of the Scutellum and 
COLEOPTILE. 
The scutellum is the hypogeal ab- 
sorptive organ. Regel, Hofmeister, and 
Gris regarded it as of axial nature ; 
Agardh as the tegument of the endo- 
sperm. The majority have held it to be 
either an entire cotyledon or part of 
one. Treviranus, Bischoff, Demoor, Le 
Maout et Decaisne, Hackel, Warming, 
Bruns, Coulter, belong to the first group. 
Those who regard scutellum and coleo- 
ptile (or plumular sheath) as together con- 
stituting the cotyledon include Mirbel, 
Cassini, ’Raspail, Bernhardi, Klebs, Schlic- 
kum, Hanstein, Hegelmaier, Fleischer, 
Celakovsky, van Tieghem. In most of 
these last cases the scutellum is described 
as the lamina of the cotyledon, and the 
coleoptile as the sheathing portion, or 
else the ligule, or a pair of fused stipules. 
Of these various views as to the 
nature of the scutellum, the last one, 
to which the majority subscribe, is almost 
certainly the correct one. Hanstein’s 
development have clearly demonstrated 
and figures indicate. He says : ‘ The 
earliest origin of the upper circular protective rim from a forwardly and 
downwardly directed outgrowth of the already differentiated first leaf 
unmistakably shows it to be a sheathing portion of the latter. This is 
confirmed by its subsequent growth around the anterior and lower side of 
Fig. 2. ZeaMais. Seedlings with the 
grain removed, seen from the dorsal (a) 
and ventral (b) sides, showing the radicle, 
adventitious roots, scutellum (sc), forked 
coleoptile (cl), and plumule (pi). 
excellent researches into the 
this, as both his description 
