24 
tion, of hereditary actions and dispositions in our domesticated animals, and 
their parallelism (subject to having less time) to the instincts of animals in 
a state of nature; bearing in mind that in a state of nature instincts do cer- 
tainly vary in some slight degree; bearing in mind how very generally we 
find in allied but distinct animals a gradation in the more complex instincts 
which show that it is at least possible that a complex instinct might have 
been acquired by successive steps, and which moreover generally indicate, 
according to our theory, the actual steps by which the instinct has been ac- 
quired, inasmuch as we suppose allied instincts to have branched off at 
different stages of descent from a common ancestor, and therefore to have 
retained, more or less unaltered, the instincts of the several lineal ancestral 
forms of any one species: bearing all this in mind, together with the cer- 
tainty that instincts are as important to an animal as their generally corre- 
lated structures, and that in the struggle for life under changing conditions, 
slight modifications of instinct could hardly fail occasionally to be profi- 
table to individuals, I can see no overwhelming difficulty on our theory. 
Even in the most marvellous instinct known, that of the cells of the hive- 
bee, we have seen how a simple instinctive action may lead to results which 
fill the mind with astonishment.« 
»Moreover it seems to me that the very general fact of the gradation of 
complexity of instincts within the limits of the same group of animals; and 
likewise the fact of two allied species, placed in two distant parts of the 
world and surrounded by wholly different conditions of life, still having very 
much in common in their instincts, supports our theory of descent, for they 
are explained by it; whereas if we look at each instinct as specially endow- 
ed, we can only say that it is so. The imperfections and mistakes of in- 
stinct on our theory cease to be surprising; indeed it would be wonderful 
that far more numerous and flagrant cases could not be detected, if it were 
‘ not that a species which has failed to become modified and so far perfected 
in its instincts that it could continue struggling with the co-inhabitants of 
the same region, would simply add one more to the myriads which have be- 
come extinct.« 
»It may not be logical, but to my io it is far more satisfactory 
to look at the young cuckoo ejecting its foster-brothers, ants making slaves, 
the larvae of the Ichneumonidae feeding within the live bodies of their prey, 
cats playing with mice, otters and cormorants with living fish, not as in- 
stincts specially given by the Creator, but as very small parts of one general 
law leading to the advancement of all organic bodies: — Multiply, Vary, let 
the strongest Live and the weakest Die.« 
IV. Personal-Notizen. 
Necrolog. 
Am 21. December 1883 starb in Berlin Prof. Carl Bog. Reichert, 
geb. am 20. Decbr. 1811. Durch seine entwicklungsgeschichtlichen, auch 
auf Gewebsentwicklung gerichtete Arbeiten gehôrte er zu den bedeutendsten, 
anregendsten und erfolgreichsten Förderern der wissenschaftlichen Neu- 
gestaltung der Morphologie. 
Druck von Breitkopf & Härtel in Leipzig. 
