58 
THE AMERICAN BOTANIST. 
shag-bark. In the wild state there is great variation in the size of 
the nut, and also in the thickness of the shell. The nut that comes 
to northern tables usually requires a nut-cracker to open it ; but in 
its native home it is not uncommon to find trees bearing nuts with 
shells so thin that they can be easily crushed in the hand. When 
fresh the kernel can usually be gotten out entire. 
How Certain Fruits Ripen. — Ever}-body knows that when 
the persimmon appears to be ripe it is not always edible. We 
must wait until time has taken the astringency out of it. The the- 
ory is that in fruits of this nature there is present a certain fer- 
ment of ''enzyme," which gradually makes it mellow and sweet. 
Other less noticeable examples of the action of such ferments may 
be found in the apple, quince and banana. 
Abrus Precatorius. — This is the name of a pretty climbing 
plant with scarlet egg-shaped seeds spotted with black, which is 
said to be coming into favor in American gardens. The plant is 
native of India, and, according to Indian Gardening, goldsmiths 
there use the seed as the unit of weight, the ruttee. The Brah- 
mins and Buddhists use it in the shape of beads for rosaries : hence 
the specific name precatorius, signifying prayer. The leaves and 
roots have the same properties as liquorice. 
The Prickly Pear in Australia. — Australia seems to be a 
land that offers superior inducements to any plant or animal of 
other lands which cannot do well at home. A while ago the meek 
little rabbit was terrorizing the settlers, and now the prickly pear 
(Opuntia) is having the same sort of vogue. So alarmed have 
the planters become that the Department of Agriculture of 
Queensland is to cft'er a substantial reward for the discovery of 
some means of eradicating the plants. From our knowledge of 
the prickly pear, it would seem that if the plant spreads rapidly 
enough in Australia to be a menace to farming it must have 
greatly altered its habits on going abroad. 
The Camphor Tree. — A large number of young camphor 
trees are growing at Audubon Park in Xew Orleans, and are of 
unusual interest to the botanist from their close resemblance to our 
