ered to be "no less than whole sidereal
systems,"[47] some of which might "well outvie our Milky Way in
grandeur." He admitted, however, a wide diversity in condition as well
as compass. The system to which our sun belongs he described as "a very
extensive branching congeries of many millions of stars, which probably
owes its origin to many remarkably large as well as pretty closely
scattered small stars, that may have drawn together the rest."[48] But
the continued action of this same "clustering power" would, he supposed,
eventually lead to the breaking-up of the original majestic Galaxy into
two or three hundred separate groups, already visibly gathering. Such
minor nebulae, due to the "decay" of other "branching nebulae" similar to
our own, he recognised by the score, lying, as it were, stratified in
certain quarters of the sky. "One of these nebulous beds," he informs
us, "is so rich that in passing through a section of it, in the time of
only thirty-six minutes, I detected no less than thirty-one nebulae, all
distinctly visible upon a fine blue sky." The stratum of Coma Berenices
he judged to be the nearest to our system of such layers; nor did the
marked aggregation of nebulae towards both poles of the circle of the
Milky Way escape his notice.

By a continuation of the same process of reasoning, he was enabled (as
he thought) to trace the life-history of nebulae from a primitive loose
and extended formation, through clusters of gradually increasing
compression, down to the kind named by him "Planetary" because of the
defined and uniform discs which they present. These he regarded as "very
aged, and drawing on towards a period of change or dissolution."[49]

"This method of viewing the heavens," he concluded, "seems to throw them
into a new kind of light. They now are seen to resemble a luxuriant
garden which contains the greatest variety of productions in different
flourishing beds; and one advantage we may at least reap from it is,
that we can, as it were, extend the range of our experience to an
immense duration. For, to continue the simile which I have borrowed from
the vegetable kingdom, is it not almost the same thing whether we live
successively to witness the germination, blooming, foliage, fecundity,
fading, withering, and corruption of a plant, or whether a vast number
of specimens, selected from every stage through which the plant passes
in the course of its existence, be brought at once to our view?"[