421 
ever, whose opinion must have great weight in all questions relating to Fungi, 
argues against these notions in the following manner : “ The sporules are so 
infinite (in a single individual of Reticularia maxima I have counted above 
10,000,000), so subtile (they are scarcely visible to the naked eye, and often 
resemble thin smoke), so light (raised, perhaps, by evaporation into the at- 
mosphere), and are dispersed in so many w^ays (by the attraction of the sun, 
by insects, wind, elasticity, adhesion, &c.), that it is difficult to conceive a 
place from which they can be excluded.” I give his words as nearly as pos- 
sible, because they may be considered the sum of all that has to be urged 
against the doctrine of equivocal generation in Fungi ; but without admitting, 
by any means, so much force in his statement as is required to set the ques- 
tion at rest. In short, it is no answer to such arguments as those just ad- 
verted to. It seems to me that a preliminary examination is necessary into 
the existence of an exact analogy between all the plants called Fungi ; a ques- 
tion wffiich must be settled before any further inquiry can be properly entered 
upon. That a number of the fungus-like bodies found upon leaves are 
mere diseases of the cuticle, or of the subjacent tissue, is by no means an un- 
common opinion ; that many more are irregular and accidental expansions of 
vegetable tissue in the absence of light, is not improbable ; and it is already 
certain that no inconsiderable number of the Fungi of botanists are actually 
cither, as various Rhizomorphas, the deformed roots of flowering plants grow- 
ing in cellars, clefts of rocks, and walls ; or mere stains upon the surface of 
leaves, as Venularia grammica ; or the rudiments of other Fungi, as many of 
Persoon’s FibriUarias. Those who are anxious to inquire into these and other 
points, are referred to Fries’ works generally, to the various writings of Nees 
von Esenbeck, and to the Scottish Cryptogamic Flora of Greville. In the 
ensuing list of genera, I have chiefly availed myself of the writings of Fries ; 
but I must confess that in the Gasteromycetes and Coniomycetes the opinions 
of that learned Botanist are so unsteady, that I cannot but view the whole sub- 
ject as being still in want of much more investigation. That it must be a mat- 
ter of extreme difficulty to form any precise opinion concerning Fungi, without 
long experience, will be apparent from the observations of Fries upon the ge- 
nus Thelephora. {Elenchus, p. 158). He asserts that out of mere degenera- 
tions or imperfect states of Th. sulphurea, the following genera, all of which 
he has identified by means of unquestionable evidence, have been constructed ; 
viz., Athelia of Persoon, Ozonium ofPersoon, Himantia of Persoon, Sporotri- 
chum of Kunze, Alytosporium of Link, Xylostroma, Racodium of Persoon, 
Geratonema of Persoon, and some others. Th. Nees von Esenbeck also as- 
sures us that the same fungoid matter which produces Sclerotium Mycetospora 
in the winter, developes Agaricus volvaceus in the summer. It would thus 
seem that the opinions of those who have asserted that the species or genus 
of a Fungus depends not upon the seed from which it springs, but upon the 
matrix by which it is nourished, are correct ; especially if we take the above fact 
in connection with the experiments of Dutrochet, who obtained different genera 
of Mouldiness at will, by employing different infusions. He says that certain 
acid fluids constantly yield Monilias, and that certain alkaline mixtures equally 
produce Botrytis. Ann. des Sc. 2.ser. 1. 30. For a description of the gradual 
developement of an Agaric, see this ingenious observer’s memoir in the Nouv. 
Ann. du Mus. vol. 3 p. 76. For the views of Unger upon spurious fungi, 
which are nothing but morbid conditions (eruptions) of vegetable matter, see 
the Ann. des Sc. vol. 2. n. s. 209 ; and Berkley’s remarks thereupon, in 
Hook. Brit. FI. vol. 2. pt. 2. p. 361. 
Geography. The Fungi by which most extra- tropical countries are inha- 
bited are so numerous, that no one can safely form even a conjecture as to 
the number that actually exists. If they are ever fortuitous productions, the 
