28 o 
Ewart, — On the Leaf-glands of 
were cut from leaves of various ages. But the gland was 
already considerably advanced in leaves whose blade measured 
only 6 mm. in length ; and it was found necessary to imbed 
the minute leaves of the axillary buds in paraffin, after 
staining in bulk with haematoxylin. In this way a complete 
series of the successive stages was obtained. I frequently 
found that the lowest (oldest) leaf of a bud exhibited no trace 
of a gland, and in cases where the bud was allowed to develop, 
this leaf often remained stunted, and more rounded in outline, 
partaking probably of the nature of a bud-scale. 
In its earliest stages the gland commences as a simple 
invagination or pit of the epidermis. It appears at about the 
same level on the two sides of the base of a leaf, at the 
junction of the lamina with the very short petiole. The 
lamina of so young a leaf is only about i mm. long. A dia- 
grammatic representation of a transverse section through the 
glandular region is given in Fig. 6, the gland itself in Fig. 7. 
The simple tube, which subsequently becomes the duct of the 
gland, dilates into a spherical cavity at its inner end, which 
may be traced through five or six successive sections. 
In the next leaf of the bud, whose lamina had attained 
a length of 2*5 mm. from base to apex, the dilatation at the 
end of the duct had become wider, and the epidermal cells 
which line it were sharply marked off from those which 
formed the walls of the duct (see Fig. 8 s. el). The epidermal 
cells at the mouth of the duct were also dividing and proli- 
ferating by septa parallel to the' surface as well as perpendi- 
cular to it. Fig. 9 represents a longitudinal section through 
the other gland of the same leaf. The lumen of the gland 
can at this stage be traced through ten or eleven successive 
sections, either longitudinal or transverse. 
The lamina of the third youngest leaf of the bud had 
attained a length of about 5 mm. ; and the gland had reached 
a stage practically the same as that in one of the youngest 
leaves on the main shoot ; a transverse section through the 
gland of the latter is shown in Fig. 10. The duct has become 
wider, and the epidermal cells lining it have undergone 
