402 
General Topics. By Dr. A. Seitz. 
protective means for their defense in the struggle of existence, which is particularly violent and pitiless in the 
open country of Tropical Africa. So for instance the larva of Cerura argentina is not adapted to the green 
foliage as that of all the other Cerura , but although it is likewise provided with a hood and forked tails, it 
exhibits white colouring with black dots, which makes it visible from afar. As they live on a Flacourtiacea, 
which family we know to comprise very poisonous plants (containing much hydrocyanic acid), the insect shows 
a warning colour, in contrast with its unpoisonous allies (feeding on poplar or willow) which are concealed by 
excellent protective colouring. Nevertheless, on being attacked, it descends, according to observations made 
by Arnold Schultze, on a thread to the ground, whereas the green larvae of Centra offer resistance clinging 
so tightly to the branch they are sitting on, that they are almost torn to pieces, before they let go. 
All the distinctive properties of the Notodontulae, their internal unprotectedness (safe for few exceptions, 
such as the one mentioned above), their excellent adaptation to the background, the entirely nocturnal habits 
of their imagines which avoid the sun, the inability of the imagines to feed on any flowers, and many other 
characteristics indicate them to belong to a very old branch of the lepidopteral tribe. Accordingly, the family 
abounds in monotypical genera, i. e. in a gi’eat many species the differentiation is already extended to structural 
peculiarities which necessitate not only a specific but also a generic separation. The Ethiopian Notodontidae 
are divided among nearly 100 genera, no less than 47 of which contain but 1 Ethiopian species. 
In contrast with the excellent adaptation to lifeless objects such as small pieces of bark, small stones, 
small fruits, dry leaves etc. we have not heard of any cases of mimcry i. e. of any imitation of other animals, 
particularly of insects, from which we might conclude a transformation of Notodontulae according to live models. 
It is not to be wondered at that there are some white or yellow species resembling equally sized and coloured 
Lymantriidae. Antheua rhodeosemena, for instance, shows a certain resemblance to some Euproctis , and the 
small white Hanthodonta debilis looks almost like some African Laelia. But the Ethiopian Antheua resembles 
much less African species than some Indian ones (such as E. barbara from Borneo etc.) and besides it by no means 
deviates from its generic allies, since nearly all the Antheua are of a very monotonous yellow, so that the yellow 
garb cannot be designated as borrowed. The resemblance of rather small, entirely white Noctuids to one another 
is also not remarkable, since the exterior resemblance of lepidoptera from our fauna, such as that of Porthesia 
similis to Leucodonta bicolor a, or of Euproctis chrysorrhoea to Stilpnotia salicis has never yet been regarded as 
the effect of mimetic assimilation. — Moreover, such mimicry would be incomprehensible. Nearly all the lepi¬ 
doptera protected by poisonous food belong to more recent families which can never have served as models 
to the older lepidopteral forms, as the Notodontulae, because they cannot have existed at the time of their 
formation. 
Already in Vol. II I pointed out that, as to the biology of the Notodontidae, the larvae are decidedly 
more interesting than the imagines. Packard has shown by the American Notodontidae that in spite of the 
most striking disfigurement of the a d u 11 larvae numerous marks are still to be found in the young insects, 
which prove the family to be very uniform. We know, however, still too little of the early stages of the Ethiopian 
Fauna to enable us to extend our researches also to them. We find a most common and striking formation, 
the so-called neck-horns, occurring in nearly all the young larvae, which can be attributed to the Notodontidae, 
but it soon disappears again in the growing larvae. Besides there is very often on the 4 th segment a protu¬ 
berance which may represent a hood {Cerura), a knob ( Pygaera ), a sting ( Hoplitis ), a hump, horn, prong, or 
the like. This appendage serves as nothing more than defence of that part in the larva, formed by the creeping 
movement on that ring which, owing to the absence of feet, stands up highest and is most exjiosed, and it 
serves the same purpose as the hump of so many Geometrid larvae, which must naturally be in the centre of 
their dorsum forming the highest place, while the striding Geometrid larva curves its body: Tornos rubiginosana, 
Nematocampa filimentaria, Endropia textrinaria, Phalaena syringaria, Opisthograptis luteolata etc. (Packard). 
It is also through the larvae that we gain information about the relationships of the Notodontidae. We 
may regard them as that lepidopteral branch which has issued from Lithosiid-like forms, from which the 
Ceratocampidae have developed, which last form a transition to an older and a younger branch. The older one 
is represented by the Saturnidae, the younger one by the Sphingidae. Thus both are closely allied to the 
Notodontidae by transitions. We may regard the raised and frequently hunched last segment of the Notodontid 
larvae as the primary stage of the Sphingid horn which in certain Notodontidae, such as Damila banksiae from 
Australia, is already perfectly developed as in a genuine Sphingid. In the course of this further development 
of the Notodontidae by way of the Ceratocampidae and Saturnidae to the Sphingidae, the larval shape leads 
from the terrifying figure to the method of perfect mimicry, from which we may infer the phylogenetic age of 
the families. The Notodontid larvae represent phantastic terrifying figures; the larvae of the Cerura, Stauropus *), 
*) The larvae of Stauropus were presumed to copy other insects or articulata; the models were told to be either forest- 
bugs or ants or also spiders. The behaviour, however, and particularly the motions of the larvae of Stauropus do not justify 
this opinion. 
