32 
CENTRAL HALL. 
remaining three, VIII., IX., and X., are for the morphology 
of the vegetable kingdom : the first containing the Cryptogams, 
the next the Gymnosperms and the Monocotyledons, and the 
last the Dicotyledons. By this arrangement the lowest or 
simplest forms of animal or plant life, those on the border- 
land, as it were, of the two kingdoms, will be brought into 
contact, and at the two ends of the series, in Bays I. and X., 
will be found the groups which show in the highest degree 
the special attributes of the division to which they belong. 
Cryptogams., j n g a y VIII. are illustrations of the general characters of 
Bay VIII 
' the Cryptogams, one of the two great sub-kingdoms of the plant 
world, and distinguished from the Phanerogams — the flowering 
or seed-plants — by the absence of a seed. Except in some of 
the lowest forms sexual reproduction occurs, but the oospore, 
the result of the union of the male and female cells, does not 
develop into an embryo and remain enclosed within a seed-coat 
formed from the tissue of the mother plant. 
In the first group of Cryptogams which occupies the wall-case 
on the left, the plant shows no distinction into root, stem, and 
leaf, but consists of a more or less uniform structure called a 
Thallus ; hence the name Thallophytes. The lowest forms, or 
Protophytes, are unicellular organisms, and can only be repre- 
sented in such a collection by considerably magnified drawings. 
Here, as in all the Thallophytes, we distinguish two divisions, 
one of green or chlorophyll-containing plants like Protococcus, 
which lead an independent existence, and another of colourless 
plants like Bacteria, which, having no chlorophyll, are doomed 
to a parasitic mode of life. 
The rest of the case is devoted to the Alga?, Fungi, and 
Lichens. The Algae contain chlorophyll, the green colour of 
which is sometimes obscured by a red or brown colouring- 
matter, and include the sea-weeds as well as many fresh-water 
plants. The fungi have no chlorophyll, but live as parasites 
on living organisms, e.g., Bhytisma acerinum, which forms black 
spots on maple leaves, or as saprophytes on dead or decaying 
organic matter, e.g., Penicillium. The Lichens are composite 
organisms, consisting of a fungal and an algal element, which 
live together. 
The second group, or Bryophytes, include Mosses and 
