PROCEEDINGS OF THE PERTHSHIRE SOCIETY OF NATURAL SCIENCE. 
Ill 
instructive paper on “ The utilization of waste grounds for 
the cultivation of fruit,” to the Society last winter. This 
paper we will have occasion to refer to presently. The 
walk along the shore from Longforgan to Port-Allan is a 
very pleasant one, and though no specimens of special 
rarity were met with, yet the varied character of the 
banks of the fore-shore, of the river itself, and of the Fife- 
shire hills, added to the delightful weather with which the 
party were favoured, made the excursion a very enjoyable 
one. Soon after reaching the shore at Longforgan a patch 
of peat was discovered lying in the marshy ground beside 
the river. An examination of this, and the occurrence in 
it of the remains of beetles and of various plants, showed 
that it was part of the buried forest bed that underlies the 
clay, and stretches from Perth all over the Carse of 
Gowrie. Good sections of this bed were observed near the 
mouth of the Earn during the first excursion made by the 
Society last season, and will be found described in last 
year’s “Proceedings.” Though this peat bed was not 
again seen in any of the clay banks examined during the 
day, yet a bit of Scots-fir bark was found in the clay at 
about a depth of 12 feet, some miles further up the river. 
Another interesting geological find was that of a bed of 
cockle (Cardium) and other marine shells in the clay. It is 
well known that in the brick clay at Errol are beds of Arctic 
shells, but these cockles are in an apparently much younger 
clay, and present a very different aspect. An account of 
their geological history, however, must be reserved in the 
meantime. Amongst the more notable plants observed 
were various maritime species, the rarest of which (in 
Perthshire) is Sagina maritima, which had not before been 
noticed higher up the estuary than Kingoodie. A more 
interesting plant is the fungus JEcidium rubellum, parasitic 
on leaves of dock, on which it forms brilliant crimson 
patches, dotted with the white star-shaped cups of the 
mature fungus. Apart from the beauty of the plant it is 
of great interest as being one of the fungi in which the 
curious phenomenon of hetercecism has been proved. This 
means that not only is the fungus parasitic on two entirely 
different kinds of plants, but that on these it assumes such 
a very different form that till recently they were supposed 
to be two kinds of fungi having no relation to each other. 
It must not be supposed, however, that the two forms of 
the fungus occur indifferently on one or other of the host 
plants. On the contrary, they form in their life history a 
cycle or alternation of generations. For example, the one 
just mentioned, that forms the cups on dock-leaves, pro¬ 
duces its spores or seeds, which, however do not reproduce 
the same form of fungus, but, being blown by the wind on to 
the leaves of the common reed, germinate there and produce 
quite a different looking fungus, which occurs in the form 
of dark brown powdery patches, the pseudospores (or 
false spores) of a Puccinia. These in their turn germinate 
and produce other spores, which find their way to the 
dock leaves and produce the above-mentioned JEcidium. 
This phenomenon is now known to occur in a number of 
fungi and in some there are even more than two stages in 
the cycle. A knowledge of this fact is not of botanical 
interest merely, but of great importance to agriculturists, 
for the well-known and frequently-destructive “ rust ” 
which attacks wheat, is the stage of a fungus which re¬ 
quires the barberry for another of its stages, and conse¬ 
quently it has been proved that where barberry bushes are 
growing in the neighbourhood of wheat fields, the wheat is 
liable to be much attacked by “ rust,” and a cure has been 
effected (or rather the attack prevented) by destroying the 
barberry bushes. After finding the JEcidium rubellum on 
the dock leaves a search was made amongst the reeds, 
which are so conspicuous a feature on the foreshore of the 
river, for the Puccinia stage of the fungus, and specimens 
of it were found on the dead stems. It was net to be ex¬ 
pected that it would be found in a fresh condition, as it is 
in autumn that this stage occurs, and what were found 
were merely the dried remains of last year’s production. 
Another fungus of interest that turned up is one (Synchit- 
rium taraxaci) that is parasitic on the dandelion, and the 
chief interest attaching to it is that it had not apparently 
been previously growD in Scotland. Amongst higher 
plants one must be specially noticed. This is the lady’s 
smock or cuckoo bud ( Cardamine pratensis ), a plant com¬ 
mon enough in damp meadows, but seldom seen in such 
profusion as in one small meadow near the river, where 
its pale purple flowers perfectly carpeted the ground. On 
examining some of the plants a curious (but not unknown) 
malformation was found, in which the flower is quite per¬ 
fect except the pistil. This, or rather the part of it known 
as the ovary, which contains the young seeds, is so altered 
that the ovules or young seeds have retrograded into 
petals. The blossom when it first opens is apparently 
normal, but in the course of a day or two the stalk of the 
pistil lengthens, and a second or double flower is produced 
inside of the first. 
Passing over several other interesting “ finds,” as 
well as the adventures of the party in crossing several 
“pows” deep with slimy mud, it will be sufficient to say 
that in due time Errol was reached, when Mrs Robertson 
very hospitably gave the excursionists tea, which, 
after the heat of the day, was as welcome as it was 
unexpected. As great a treat followed in the form 
of an inspection of Dr Robertson’s garden, which 
