431 
to study the papers of Bory de St. Vincent, and Fries, for general ideas, the 
various articles cited at the head of this article, and that most beautiful of all 
books, the AlgcE Britannic^ of Greville, together with the second volume of 
Hooker’s British Flora, for the application of them to the Flora of this 
country. 
Those who have ever examined the surface of stones constantly moistened 
by water, the glass of hothouses, the face of rocks in the sea, or of walls where 
the sun never shines, or the hard paths in damp parts of gardens after rain, 
cannot fail to have remarked a green mucous slime with which they are co- 
vered. This slime consists of Algae in their simplest state of organisation, 
belonging to the genera Palmella, Nostoc, Red Snow, and the like, the Nos- 
tochinae of Agardh, or Chaetophoroideae of Greville ; they have been called 
Chaodineae by Bory de St. Vincent, whose account of them is to the following 
effect : — The slime resembles a layer of albumen spread with a brush ; it ex- 
foliates in drying, and finally becomes visible by the manner in which it co- 
lours green or deep brown. One might call it a provisional creation waiting 
to be organised, and then assuming different forms, according to the nature of 
the corpuscles which penetrate it or develope among it. It may further be 
said to be the origin of two veiy distinct existences, the one certainly animal, 
the other purely vegetable. This matter lying among amorphous mucus con- 
sists in its simplest state, of solitary, spherical corpuscles, (such as are figured 
by Turpin in the Memoires du Museum, vol. 18. t. 5. ; and as may be easily 
seen in the common green crust upon old pales, PalmeUa botryoides) ; these 
corpuscles are afterwards grouped, agglomerated, or chained together, so pro- 
ducing more complex states of organisation. Sometimes the mucus, which 
acts as the basis or matrix of the corpuscles, when it is found in water, which 
is the most favourable medium for its developement, elongates, thickens, and 
finally forms masses of some inches extent, which float and fix themselves to 
aquatic plants. These masses are at first like the spawn of fish, but they soon 
change colour and become green, in consequence of the formation of interior 
vegetable corpuscles. Often, however, they assume a milky or ferruginous 
appearance ; and if in this state they are examined under the microscope, they 
will be found completely filled with the animalcules called Naviculariae, Lunu- 
lins 0 , and Stylarise, assembled in such dense crowds as to be incapable of 
swimming. In this state the animalcules are inert. Are they developed here, 
or have they found their way to such a nidus, and have they hindered the de- 
velopement of the green corpuscles ? Is the mucus in which they lie the same 
to them as the albuminous substance in which the eggs of many aquatic animals 
are deposited ? At present we have no means of answering these questions. 
According to Gaillon, many of these simple plants are certainly nothing but 
congeries or rows of the singular and minute animalculae called Vibrio tri- 
pun ctatus and bipunctatus by Muller, strung end to end. See Ferussac’s 
Bulletin, Feb. 1824. He there particularly applies this remark to Monema 
comoides ; in his paper on Nemazoaires in the Ann. des Sc. new series, 1. 
44., he enumerates a number of genera to which he ascribes this property. 
Another form of Algae, one which may be considered a higher degree of 
developement of the last, is that in which they assume a tubular state, con- 
taining pulverulent or corpuscular matter in the inside, and become what are 
called Conferv’se, or, as Bory styles them, Arthrodieae. These, which com- 
prehend true Confervae, Oscillatorias, and many Diatomeae, are thus spoken 
of by the botanist last mentioned : — ^The general character of Arthrodieae 
consists in filaments, generally simple, and formed of two tubes, of which one, 
which is exterior and transparent, offers no trace of organisation to the most 
powerful eye, so that it might be called a tube of glass, and contains an inner 
articulated filament filled with colouring matter, often almost imperceptible, but 
