199 
-THE GEELONG NATURALIST, SH 
across the sand dunes. We noticed that the markings were 
almost in a straight line from the beach to the scrub, where 
we saw these crabs disappear. From these observations we 
would infer that these crustaceans when journeying travel in 
numbers and in nearly a direct line to some given locality, 
and that their excursions are made during the night. 
Another peculiarity in this species of crustacean is that 
of running sideways. I have watched them with interest, 
both while walking forward and running. Forward move- 
ments seem slow and awkward, but their side movements are 
so to speak graceful and quick. Onstudying these movements 
there are two reasons which I think would account for this 
sideway peculiarity: first, that a better balance of the 
creature's body would be attained; and second, that a smaller 
space or hole could be entered sideways by this creature than 
if it entered cover frontways. I have examined their 
burrows, and have found them much smaller than the body 
ofthe creature is broad, but at the end of the burrow it is 
widened out to the whole width of this peculiar and interesting 
creature. 
A NOTE ON THE PHYSIOLOGY OF PLANTS, 
Bv tHe Rev. J. S. Hart, M.A., B.Sc, * 
Tue physiology of plants is perhaps a little outside the 
domain of the field naturalist, though it would be well if 
some of them could add simple experimental work to their 
observations of the facts of nature. It should be interesting, ` 
however, to all botanists to know something of the life- 
processes of plants. 
Recent investigations on the subject of the absorption of 
nitrogen are yery suggestive. It has long been held that no 
plants are able to absorb that gas from the atmosphére, but 
it has been discovered that amongst the bacteria this power is 
possessed. Accordingly, experiments were conducted on 
other very simple organisms, especially uni-cellular algze, with 
negative results. | 
. But it is very interesting to find that when these algae and 
the bacteria grow together, the power of the latter to assimi- 
late nitrogen from the air is very much increased. There is, 
in fact, a symbiosis—the algæ assimilating carbon especially, 
and the bacteria nitrogen. Is it not possible that the same 
thing occurs in lichens, and that in them the alge are assisted 
by a nitrogenous assimilation going on in the fungus? At 
all events it should be worthy of investigation. 
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