24 Compound Organisms and their Lessons. [January, 
Aphides or plant-lice. The eggs of these pests, after 
remaining dormant through the winter, give rise to a brood 
consisting solely of females. These again, in turn, without 
impregnation, deposit so-called eggs, — more correctly pseud- 
ova, — from which spring nothing but females. So the pro- 
cess continues through the summer. But in the autumn the 
last brood consists of both sexes, and the impregnated eggs 
now produced remain through the winter. If the reader 
will turn back he will see that this process of reproduction 
is almost exactly identical with what we have noticed in the 
Nais. There, too, we found a succession of individuals 
formed by budding, and able to reproduce themselves by 
budding alone, until the series is finally terminated by an 
individual capable of producing eggs. The unimpregnated 
egg, or pseud-ovum, of the Aphis is the representative of the 
bud of the Nais. If we adopt the view that all that pro- 
ceeds from a single egg is an individual animal, then all the 
descendants of an Aphis of the autumn brood form along 
with it one individual, separate bodily, but connected in their 
development. Such a succession of Aphides is therefore a 
compound animal. 
Full parthenogenesis does not, so far as has been traced, 
occur in the Vertebrata, although the unimpregnated egg 
of several species has been known to undergo the first rudi- 
ments of segmentation. This may well be considered as 
one of those cases of “reversion” which show that the 
higher animals are sprung from forms in which gemmation, 
and consequently compound existence, are normal. 
Even in the anthropoids, and in man himself, there are 
faCts which point in the direction of a complex personality. 
The two-headed monstrosities which have been brought into 
the world, and as a rule hastily dismissed out of it, if care- 
fully observed during life and as carefully dissected after 
death, would not merely raise, but possibly aid in solving, 
certain questions which go to the very root of our idea of 
personality. 
A simpler phenomenon of daily occurrence is the presence 
in man, and as part and parcel of his system, of certain mi- 
nute organisation — to wit, the white-blooded corpuscles. 
Many biologists would place these particles on a level with 
certain of the Protozoa. Thus human life and the life of 
every higher animal would be complex indeed, including the 
lives of myriads of microbia. Do they exist for our sake, 
or we for theirs ? These questions are unscientific, but they 
are on a level with some which are still too frequently asked. 
