1076 Marvels of the Universe 
on the approach of fine weather. This 1s really a hygrometer worked by pieces of twisted catgut, 
which expand when the air is dry and contract in the presence of moisture. More rarely we may 
come across a simpler and more natural hygrometer in the shape of a large oat-fruit mounted on 
a piece of card, which the cottager will assure you is an infallible weather indicator. This, they 
will tell you, is not the common oat, but one of a rare 
kind hard to come by and, therefore, to be treasured 
accordingly. We heard recently of the possessor of 
one of these who declared she had been offered five 
shillings for her “ barometer,” but she knew better than 
to part with it! 
Everyone knows that in the growing of the 
common oat the fruit contains two or three seeds or 
oats, and that certain of the enveloping scales or 
chaff end in long, slender bristles or awns. 
There is a species introduced from North Africa 
in which these awns are a couple of inches long 
with a sort of knee half-way. Below the knee the 
awn is thick, unbending, and spirally twisted ; above 
it tapers from the knee to a very fine, hair-like 
point. 
The cottager will tell you that when rain is coming 
both awns will bend over to the left. When they 
bend to the right fine, dry weather is sure; and when 
a change is in progress the awns cross each other in 
the centre. There is a certain amount of truth in 
this, for the twisted awn is highly hygrometric. But 
every oat-fruit gathered from the same plant and 
similarly mounted will not behave in the same 
way. One will be pointing to the right and another 
to the left under the same meteorological conditions. 
Still, by mounting one specimen only and noting 
its behaviour under different conditions, it will serve 
as a guide to the humidity of the air. 
But the real marvel of this Animated Oat does 
not consist in its weather indications, but in its 
natural purpose. 
Its hygroscopic property is really an ingenious 
plan for burying the seeds. The bent-kneed awns 
are levers for pushing the seed into the soil. 
FEA LSE As the ripe fruit falls from the oat-plant to 
ANIMATED OATS. the ground the tip of one awn and the point of 
The photo shows three different positions of the the fruit are in contact with the soil. The base 
cee aaa sir Gh teoce meaner ears of the fruit is furnished with brushes of golden- 
ing to the amount of moisture in the atmosphere. brown stiff hairs, arranged in semi-spirals, and these 
are also acted upon by moisture and dryness, closing up or standing out at an angle. The 
effect of the lengthening movement of the awns is to screw this point into the soil, and the hairs 
act as barbs to prevent its withdrawal when the awns contract. The action is much like that of 
the Stork’s-bill fruit already described in this work (page 193). Its power may be demonstrated 
by holding one in the closed hand, when it will be felt making its way between the fingers. 
