1884.] Colonial Organisms. 245 
As for the reproductive phenomena of the animals’ here con- 
sidered, there is no essential distinction from those of the colo- 
nial class. In the low forms the young are born immature, in 
the high forms they are born mature, but in’ all ‘cases their real 
birth is as a single cell into the ovary, while the after develop- 
ment is gained partly within the maternal body or the egg, partly 
in the external world. Yet’ in this respect the highest vertebrate 
presents an interesting parallelism with the highest arthropod. As 
the ants continue to feed the embryo after birth until it has as- 
sumed the mature form and is able to obtain’ its wm subsistence 
in the method of the mature animals, the sare may be said of 
the birds and the Mammalia, which continue’ to supply their 
young with food after birth until they are able to provide for their 
own needs in the parental method. Thus at the summit of the 
organic series the young begins its individual life as an animal 
mature in every function except the reproductive. ` 
The colonial origin of the higher plants is equally significant 
with that of the animals mentioned. As compared with the ani- 
mal world their closest analogy is with the colonies of the fixed 
Hydrozoa, in which, from a common stem attached to the surface, 
outgrow successive nutritive and reproductive individuals. This 
description applies exactly to the highest plants, with the excep- 
tion that they are attached to the ground by’ roots, which are also 
transformed individuals. 3 ae 
_ Even the escape of the reproductive members of the Hydro- 
zoan colonies as free Medusz is not without its analogies in the 
vegetable world, whose shed spores become reproductive indi- 
viduals. The fact is that all high development in plants is at- 
tained by the method of colonization, and that the advancement 
in this direction is far inferior to that gained by the higher animal 
colonies. she 
The lower sub-kingdoms of plants are not clearly distinct from 
cell colonies. They are born as single cells, which subsequently 
develop into cell masses. These, particularly in some of the 
higher Fungi, become very complexly organized, yet they dis- 
play little or no cell differentiation, and may properly be consid- 
ered as cell colonies. The spores, which are shed by all the 
lower Orders of plants, are free asexual offspring probably pecu- 
liar only in being specially rich in protoplasm, and thus well 
adapted to active growth. Such an asexual growth takes place 
