THE THEORY OF LICHENS. 
89 
the whole is Lichen nothing but Lichen ; and the two kinds of 
tubes, so different at first view, are but different states of the evo- 
lution of one single and individual organ. The very slender hyphal 
tubes are the first part containing the microgonidia. This first 
part may remain always in this state, or it may also enlarge and 
lengthen, while the microgonidia, originating by free formation, 
may pass into the stage of gonidia, and then the narrow hyphal 
tubes will become large gonidia-bearing tubes. 
Mimicry in Fungi. — Since my paper upon this subject, which 
appeared in September number of Grevillea, my friends have kindly 
brought other facts under my notice. Mr. W. R. Gerard was good 
enough to send me the Bulletin of the Torrey Botanical Club, for 
March, 1880, in which there is a note by him upon the “ Correla- 
tion between the odour of the Phalloids and their relative 
frequency,” in which he points out the avidity with which flies de- 
vour the foetid hymenia of these fungi, in the following words : — “ In 
fact, so similar to decaying animal organisms is it (i.e., the odour), 
that even flies are deceived thereby ; and before the ill-scented mass 
has had time to creep away, it will have been greedily devoured 
by numbers of these insects. As flies have 4 no local habitation,’ 
they give the minute ingested spores a wide dissemination by means 
of their ejections. It is a well-observed fact that the very common 
species of 4 stink horns ’ ( Phallus impudicus , indusiatus , etc.) are 
found in the greatest abundance around human habitations, where 
they occur under porches, in the door yard, and in the garden, and 
often in such numbers and so frequently as to occasion serious in- 
convenience. This tendency to become domesticated, is thus 
correlated with their foetid odour, and the presence of those constant 
companions of man — the flies. More rarely these malodorous 
plants are found in woods in the vicinity of villages and cities. In 
such localities, where flies are less abundant, the same office is often 
performed for them by other insects — especially by beetles. The 
only fresh specimen of a Phallus that I ever met with in the woods 
was being visited by several individuals of a common species of 
carrion beetle — Silplia Noveboracensis .” The writer then proceeds 
to point out that the much greater frequency of Phallus impudicus 
as compared with Cynophallus caninus, is probably due to the fact 
that the former is powerfully foetid, whilst the latter is nearly in- 
odourous. That Phallus impudicus occurs so frequently near 
human habitations in the United States is peculiar, as it certainly 
does not do so with us in Britain. Respecting the odour of 
Pilacre peter sii, my friend Mr. Worthington G. Smith has called 
my attention to the fact that it is identical with that of liquorice 
( Glycyrrhiza glabra) . During the meeting of the Woolhope Club, 
last October, Mr. H. T. Wharton drew attention to the smell of 
Lactarius camphor atus , which, when dry, exactly resembles that of 
fenugreek (Trigonella foenum-grecum). 
King’s Lynn, 7th Nov., 1881. Charles B. Plowright. 
7 
