448 
OX THE SEASONAL GROWTH OF PLANTS. 
is no appreciable difference in the verdure, yet, on examining the ligneous 
structure of the trunks, we plainly see that it is formed by pulsations, 
as it were; instance the mahogany, satin-wood, and other tropical kinds 
of wood used in manufactures. But in respect of these just mentioned, 
we are not certain that the concentric rings of wood, on a transverse 
section of the trunk, are annual layers, because, for aught we know to 
the contrary, they may be deposited at twice or even thrice in the course 
of twelve months in those exuberant climates. In this temperate 
country it has been repeatedly proved that there is a deposit of new 
wood in every year of the tree’s life ; but of tropical trees we have as yet 
had no positive proof. Travellers in those countries cannot have leisure 
to prove this matter ; and we have heard of no resident who has 
attended to this particular. 
A question occurs—is there any such a thing in any climate as an 
ever-growing tree ? Among herbs and suffruticose plants, there are, 
perhaps, many which, being placed in constantly uniform circumstances 
of heat and moisture, are ever-growing, more especially those which 
emit roots from their lengthening stems, and which at the same 
time produce both viviparous and oviparous progeny; that is both 
runners and seeds. All that are called creeping plants are ever 
extending themselves, if sufficient heat and moisture be present; but 
this process is not a constantly increasing growth of the original stock, 
but an increase of numbers or bulk of the offset progeny. Such 
instances are frequent among the grasses, whether purely herbaceous, 
like the sheep’s fescue (Fcstnca ovina ), or woody, like its gigantic con¬ 
gener, the bamboo. This latter is a stoling plant, and, in its native 
country, appears in an ever-growing state : its aggregated stems are 
ever rising in successive gradations, from the green succulent shoot, 
peeping through the soil to-day, up in various heights to nearly four¬ 
score feet. 
But if there be any plant which may be truly called ever-growing, 
we will most likely find it among the palms. The growth of these 
majestic trees really appears to gain altitude by an incessant progression, 
without manifest pause or periodical interruption. And this appears 
much more evident from examination of the internal structure of the 
stem, than from constant observation of the external development. 
Frond after frond rise from the centre of the bole, and are consecutively 
expanded ; and though we may reasonably fancy that the growth may 
be more rapid during the monsoons, there is certainly no sign of any¬ 
thing like grades to indicate cessations of growth or interceptions of the 
structure of the wood, the whole being a uniform combination of longi- 
