HICK : l ALAMOSTACHYS BINNEYANA. 
287 
The histology of the bracts has scarcely received the attention 
it seems to deserve, and is certainly more complex than has hitherto 
been made apparent. A reference to fig. 4, PL II., which represents 
a transverse section, will show that the tissues are well differentiated. 
At c we have the epidermis, which can often be followed round the 
whole section ; at b is seen the sclerenchyina or prosenchyma 
which is in continuity with that of the nodal disk ; and at v the 
delicate strand of vascular tissue. Attention should be specially 
directed however to a layer of much larger elements g which 
occupy the lower half of the bract, and form one of the most con- 
spicuous of its features. Some of these elements are unusually large, 
while their walls are comparatively thin, and their contents dense 
and carbonaceous. They appear to be united without intercellular 
spaces, and at some distance from the wall a thin pellicle is usually 
present in each cell, which may represent the primordial utricle. 
The carbonaceous mass is within this pellicle, and in most cases there 
is an interval between them, while in others they are in contact with 
one another. Occasionally both are in contact with the cell wall. 
This layer of tissue I have come to regard as an important one. 
It is a constaut character of the bracts when perfect, and has been 
found of great practical value in the recognition of fragments of 
bracts when detached and in other ways. It appears, however, to 
have been easily destroyed, as many bracts are met with in which it 
is wholly or partially lost. It scarcely needs to be said that it is a 
continuation of the similar layer mentioned above as making its 
appearance at the periphery of the nodal disk. 
Longitudinal actions of the bracts are hardly ever met with in 
a form suitable for illustration. Still by carefully studying the 
numerous fragments that occur in most preparations of the strobilus 
it is easy to make out that the elements beneath the upper epidermis 
are really sclerenchymatous, and that the layer with the black con- 
tents is made up of somewhat elongated cells with rectangular or 
oblique ends. 
The Sporangiophores. 
The sporangiophores consist of a pedicel and a peltate head or 
scutelluin, and, as shown by Carruthers and Williamson, their his- 
