94 DEVELOPMENT OF ALLIUM UKSINUM. 



surrounded the bud equally perishes. The following is the result 

 of the foregoing remarks : — 



I. — The two leaves, which exist at the time of flowering and 

 some time later, belong to two different axes ; the outer to this 

 year's basal axis which is terminated by the flower-stem, the inner 

 to the lateral axis which proceeds from the angle which the outer 

 leaf forms with the peduncle, and which in the following year is 

 terminated by it. 



II. — The leaves on the lateral axis (which next year becomes 

 with reference to the new bud the primary axis) are arranged as 

 follows : — 



1. The inner leaf (f), whose sheath forms the true bulb or 

 reservoir of nutriment when the lamina dies. It is the outermost 

 or lowest of its own axis. 



2. One (seldom two) membranaceous sheaths. 



3. Another leaf (d) which surrounds the flower-stem with its 

 sheath, and, after fruit is formed, entirely vanishes, and with 

 which the outer leaf of the involucre alternates. This leaf is 

 highest and innermost of its axis. It becomes external, however, 

 by the previous destruction of the one or two outer sheaths. 



III. — It is remarkable, that the first or lowest leaf in this 

 lateral axis is a perfect leaf, and that its evolution takes place at 

 a different period of vegetation from that of the other leaf of the 

 same axis. 



In plants which do not blossom there is normally but one 

 leaf, whose sheath equally becomes a reservoir, while the lamina 

 withers, and with it a sheath alternates : this is followed next 

 year by a leaf with a fleshy sheath. Whereas the pinncipal bud 

 in the flowering plant is axillary, it is terminal in non-flowering 

 individuals, and the leaves formed at their summit always belong 

 to one and the same axis. 



A bud is rarely found in the axil of the sheath. The multiplica- 

 tion of the plant by bulbs is rare, and seeds are therefore pro- 

 duced the more abundantly. It begins to sprout in the beginning 

 of April. The seedling plant consists of the cotyledonal leaf, 

 which is firmly fixed by the process answering to the lamina 

 within the seed ; a membranaceous sheath, a leaf which incloses 

 a little bud in its fleshy sheath, and which is, with the exception 

 of the cotyledon, in whose place we find in older examples the 

 sheathing base, constructed exactly like the older but not yet 



