32 
CEXTEAL HALL. 
and X., are for tlie morphology of the vegetable kingdora: 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 borderland, 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. In Bay 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 ProtococmSy 
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 Algae, 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 
I^lants. The fungi have no chlorophyll, but live as parasites 
on living organisms, e.g., Rhytisma acerinum, which forms black 
spots on maple leaves, or as saprophytes on dead or decaying 
organic matter, e.g., Penioillium. The Lichens are composite 
organisms, consisting of a fungal and an algal element, which 
live together. 
The second group, or Bryophytes, include Mosses and 
