PARK AND CEMETERY. 
401 
ten per cent, of the receipts from the sale of lots 
with the Norristown Title, Trust and Safe Deposit 
Company. To insure the fund being used for the 
purpose intended the by-laws have been so framed 
that this trust cannot be altered without the consent 
of the lot holders. 
The landscape work has been entirely in the 
hands of the superintendent, Bellett Lawson, Jr., 
who has been allowed by the directors to use his 
individual taste throughout. 
Riverside Cemetery is a striking example of 
what can be done in a small town with a very con- 
servative people. 
Hybrid Species. 
PRINCIPLES AND LAWS OF INTER-BREEDING OF PLANT LIFE. 
When a plant is raised from seed it will always 
bear a strong likeness to its parent, and if the spe- 
cies be one which has little tendency to variation it 
will resemble it very closely. But there are many 
species which have a great disposition to present de- 
viation from what may be considered their original 
form, and thus from seeds of the same parent it is 
often possible to produce by a difference of treat- 
ment a number of plants differing considerably 
from one another. 
Whatever such difference may be, however, 
these plants are all regarded as belonging to the 
same species, since they are descended from a com- 
mon stock, and by such experiments it is often pos- 
sible to show that plants which have been consid- 
ered as distinct species have no real title to be so 
classed. 
It is often possible, however, to produce seeds 
capable of giving origin to plants that shall com- 
bine the characters of two different races. This is 
done by placing the pollen of one species upon the 
stigma of another, so that the germ furnished to one 
shall be nursed by the other. It is not difficult to 
understand how the germ thus influenced should be 
subsequently developed into a form differing from 
that of its own parent, for the genus of cryptoga- 
mia, which are not received into any ovide, but are 
dependent upon elements alone for their support, 
are often developed, especially among the lower 
tribes, into forms very different from that which they 
would naturally present. 
Thus a mucer, a sort of fungus concerned in the 
production of moldiness, has been seen growing in 
water in a form so like that of a conifer that it was 
only recognized as a fungus when it lifted up its 
fructification above the field. 
The plant developed from a seed by the agency 
of two races is termed a hybrid. 
It is necessary in order that the seeds thus 
formed should be fertile that the parent species 
should be nearly allied to each other, and it is very 
seldom that a hybrid can be produced when they do 
not belong to the same genus. Now, if the hybrid 
bear flowers and its stigma be fertilized with its own 
pollen it may produce seeds that can be raised into 
plants like itself, and these may flower and produce 
a third generation in like manner. 
But there is no instanee in which a hybrid race 
(and this applies to the animal, as well as the vege- 
table creation), which has thus originated in the 
intermixture of two species really distinct, has ever 
been continued without intermixture beyond the 
fourth or fifth generation. The plant, when not fer- 
tile by itself, may bear seed if its stigma be sprin- 
kled with the pollen of one of its parent species, 
and its pollen may be fertile when placed on the 
stigma of either of these. 
In this manner a race intermediate between the 
hybrid and one of the parent species is produced, 
and this is continued longer just in proportion as it 
is caused to approach the pure breed by a succes- 
sive intermixture of this kind. The end of all hy- 
brid races produced between races really distinct 
appears to be, therefore, that either the race be- 
comes soon extinct, which it will do if kept sepa- 
rate, or it merges into one of the parent races, if 
continued by intermixture with either of them. This 
principle affords a valuable test for determining 
what really are and what are not distinct species, 
for if a hybrid race can be produced between them 
which continues to be fertile of itself the proba- 
bility is strong that they are only varieties. 
Cultivators of flowers are constantly in the habit 
of producing such new races between the different 
varieties of many plants. 
For instance, the South American amaryllis and 
the calceolaria. Both these species are very much 
disposed to spontaneous variation, and by selecting 
the most beautiful of the new races that spontane- 
ously originate from their seed and causing them 
to produce hybrids a still larger amount of variety, 
both in form and color, may be obtained. These 
hybrids are of equal fertility with their parents, 
since the latter are not separated by any essential 
difference. Andrew H. Ward. 
In the royal gardens at Kew there is a branch of 
what is said to be the oldest tree in the world — the 
famous dragon tree (Dracaena draco) of Oratava. 
This tree, which was destroyed by a great gale some 
years ago, was, the new weekly paper the Rocket 
says, supposed to be at least 2,000 or 3,000 years 
old — some assigned it a much longer growth. A 
branch was removed from it and brought to Kew, 
where it still thrives; it may be seen in the Econo- 
mic house. — Westminster Gazette. 
