4. chlorophyllous layer.]

All the vascular bundles in the leaves of _Aristida setacea_ have broad
sclerenchymatous bands on both the sides. Besides these bands arranged
like a girder above and below each bundle, there are on the lower side
bands of sclerenchyma. So the sclerenchyma becomes almost continuous on
the lower side.

[Illustration: Fig. 53.--Transverse section of the leaf margin of
Panicum repens. x 180

1. Sclerenchyma; 2. stomata; 3. chlorophyllous layer.]

[Illustration: Fig. 54.--Transverse section of a part of the leaf of
Aristida setacea. x 30.

1. Vascular bundle; 2. sclerenchyma; 3. motor cells.]

[Illustration: Fig. 55.--Transverse section of a portion of the leaf of
Aristida setacea. x 120

1. Motor cells; 2. stomata; 3. sclerenchyma; 4. epidermis; 5. cutin
layer.]

The sclerenchyma lying on the lower side of the primary bundles are
contiguous with the bundle, while those above are separated from the
bundle by the chlorophyllous layer. (See fig. 55.) In the case of
secondary and tertiary bundles the sclerenchymatous bands lying on the
lower side are in contact with the chlorophyllous layer, whereas the
upper bands are either in contact with this layer or separated from it
by a few parenchymatous cells.

All the vascular bundles in the leaves of _Eragrostis Willdenoviana_ are
provided with sclerenchyma on both the sides. The lower band of the
primary vascular bundles is continuous with the vascular bundle, the
chlorophyllous layer being open below. The upper bands of the primary
and the lower bands of the secondary vascular bundles just touch the
chlorophyllous layer. In the secondary bundles the sclerenchyma band
above is separated from the chlorophyllous layer by two layers of
parenchyma. In the case of the leaves of _Panicum flavidum_, _P.
colonum_, _P. fluitans_ and _Pennisetum cenchroides_ the sclerenchyma is
separated from the chlorophyllous layer by layers of parenchyma.

[Illustration: Fig. 56.--Transverse section of a part of the leaf of
Eragrostis Willdenoviana. x 30

1. Vascular bundle; 2. sclerenchyma; 3. motor cells.]

[Illustration: Fig. 57.--Transverse section of a portion of the leaf of
Eragrostis Willdenoviana. x 150

1. Motor cells; 2. stomata; 3. sclerenchyma; 4. chlorophyllous layer; 5.
vascular strand cut through; 6. hair.]

[Illustration: Fig. 58.--Transverse section of a part of the leaf of
Panicum colonum. x 30

1. Vascular bundle; 2. sclerenchyma; 3. motor