138 THE AUSTRALIAN NATURALIST. 
year in connection with the meeting of the Australasian As- 
sociation. An interesting address, illustrated with lantern 
slides and models, on Plant Hairs, was delivered by Mr. 
McKinnon, B.Sc. The exhibits were, a collection of in- 
sects from Brownsville, Miss Brewster. Mr. Vinckh, fruit 
of Monstra deliciosa. Master Oliver Edwards, Paropsis, 
collected on Eucalypts around Sydney. 
SYMBIONTS. 
By E. Cheel. 
At the meeting on 2nd April, Mr. H. Cheel exhibited a 
series of interesting specimens of plants which live in com- 
bination for mutual benefit, a relationship known by the 
Greek term ‘‘Symbiosis.’’ Parmelia sp. Probably P. re- 
ticulata, Tayl. A large foliaceous lichen measuring 163 
by 134 inches across, taken from off a sandstone rock at 
Wiseman’s Ferry. This specimen, it was explained, was 
not a simple plant in the true sense of the term, but a com- 
plex combination of two individuals—a symbiosis of an 
Algae of the Protococcus family and a Fungi. 
This form of symbiosis was first brought under notice about 
50 years ago, by De Bary, who when working on fungi and 
studying the nature of lichens, suggested that the latter 
were either the perfectly developed forms of certain elemen: 
tary green plants, or algae which had hitherto been recog 
nised only in an early stage, or that those algae assumed 
the form of lichens when they were attacked by a fungus. 
About 10 years after this hint was given, the matter was 
followed up by Dr. Schwendener, a German botanist, who 
pretty clearly showed that lichens were dual organisms, a 
symbiosis of Alga and fungus. 
Another example of symbiosis was shown in a series of 
root nodules, comprising a Wattle Acacia longifolia, Pid 
geon Peas (Cajanus indicus), French Beans (Phaseolus vuls 
garis), Flower Bean (Phaseolus sp., probably P. calcaratus), 
Bay Bean (Canavalia obtusifolia) and Glycine clandestina, 
These little nodules scattered on the roots of the legumin- 
ous plants mentioned above, are what might be termed colo- 
nies of living bacteria, which flourish in the living cells of 
the roots, not injuring the plants, but, on the contrary, act- 
ing as suppliers of nitrogen, which is used by the host 
plants; thus an advantageous attachment and co-operation 
exists between the higher plant and these micro-organisms. 
