MR. G. MAW ON THE LIFE-HISTORY OF A CROCUS. 359 
expansion within the tunics. The membranous tunics rupture 
by the corm-expansion and split up from the base; but the super- 
imposed layers maintain the continuity of the covering. The 
funetion of the reticulated structure is also obvious, allowing of 
lateral expansion, which is a!so provided for in the stranded tunie 
of Crocus Fleischeri; but this widening out laterally involves the 
vertieal drawing up of the tunic from the base of the corm, and, 
but for the presence of the basal tunie, this would be left bare. 
The claw-like rays of the usual pattern spring strongly upwards 
and inwards, and tightly grasp the base of the main tunic as it 
slips upwards. The annuli of the annulate species, with the 
rows of little teeth on their upper margins, slip over each other 
and cling with the teeth to each other and to the bottom of the 
main tunic; and in C. levigatus, where the annuli of the basal 
tunie are absent, there is an adaptation of the main tunic in its 
vandyke divisions, which strongly bend inwards and downwards 
to elasp the bottom of the corm. 
Leaf-structure.—Of the two distinct sets of leaves, the outer 
series or sheathing-leaves are much shorter and broader than the 
proper leaves, and closely envelop the base of the plant. They 
vary from three to six in number, the inner being invariably 
longer than the outer; and they graduate both in height and in 
structure in an inward direction towards the proper leaves. The 
sheathing-leaves generally fall short of, but in some species 
exceed and hide the proper spathe, a character which is suffi- 
ciently constant for specific determination. 
Fig. 3. 
Leaf-section of Crocus iridiflorus, enlarged about 10 times nat. size. 
Thenext organs we approach inan inward and upward direction 
are the proper leaves, familiarly known as “the grass" of the 
Crocus: these present a great diversity of structure. The more 
common type is represented in section in fig. 54, C. vernus, 
202 
