498 SATURNIIDAE. By Dr. A. Seitz. 
through owing to the moisture accumulated in their curvatures, imitative holes, i. e. hyaline spots replacing 
the customary eyespots. * 
This adaptation, however, as in all old families, is only expressed by copying equally old formations, 
such as leaves or bark; nowhere are traces of mimicry to be seen. Neither the larvae nor the imagines of the 
Saiurnidae imitate any other animal. Considering their shape and size, the imitation of snakes’ heads by the 
the Saturniid larvae would not have been in any way more difficult than it was for the Sphingid larvae, but 
no such example is to hand. 
Nor do the Saturniidae represent good models, for it seems quite certain that all of them are eatable. 
Both larvae and imagines are devoured by birds if they are discovered and are not so large that the attackers 
are afraid of them. In the Indian Tussah silk-nurseries, where the larvae of Antheraea are bred in the open 
air, guards must keep off the birds which menace the larvae, by means of rattles, arrows, and long rods. The 
Saturniid larvae are also greedily attacked by large insects, such as hornets and other beetles of prey, and at 
Darmstadt, where, in the middle of the last century, experiments were arranged for the wholesale production 
of Tussah silk, the breeding was frustrated by Avasps attacking the larvae of Antheraea. 
Like all the insect species which are very much exposed to the persecution by other animals, Saturniidae 
are protected by other, external means which afford them a certain safety. We have already mentioned pro¬ 
tection by adaptation. A further protection is their size which is often very considerable. From a verandah, 
where I let fly newly emerged Platysamia cecropia and Sarnia cynthia, I could observe that sparrows were 
terrified by a cecropia settling down near their nest on the wall of the house. Quite a number of the sparrows 
flew in front of the lepidopteron, opening their beaks with cries and flapping their Avings, Avithout daring to 
approach the insect. S. cynthia, darting about AA r ere not molested by any Muscicapa which othei'AA’ise pursue 
every Noctuid or Notodontid. 
Moreover, the flight of the Saiurnidae is rather swift and extremely restless. An A glia on being pursued 
frequently doubles, and Eudia pavonia mostly only flies in a straight line when it is not disturbed. The uirwieldv 
$$ being prevented by their structure from such flying-tricks fly at night, even those species the BS of AAdiich 
swarm in the daytime in the sunshine, such as A glia tau. 
Of a much greater value, however, is the protection bestowed by Nature on some larvae. Certain larvae 
of this family cannot be caught hold of without the hand sustaining very great burning pain. In fact, the hand 
touching some larvae from the American genus Automeris (Hypercldria ) feels as if it had been put into a nettle- 
bush, and the pain lasts for a long time. The ramulous thorns by which the insect is protected on all sides 
contain regular nettle-threads, the poisonous sap of which is stored up in tube-like expansions beneath the dorsal 
skin and is secreted by specially adapted glands. F. Heim proved the burning effect of the Saturnidae upon 
other assailants even in those cases, where the human skin is not effected. Should such hairs, as for instance 
those of the larvae of Eudia pavonia, be pressed at the base, they immediately break off, and at the broken 
place we notice a drop of liquid, the acid character of which coidd be ascertained by litmus paper. 
Most of the Saturniid larvae live on trees and prefer Avood-j)lants. The colour of the adult larvae is 
adapted to that of leaves, but that of the young larvae is frequently black, and in the species protected by 
burning effect the colour itself seems to be of no great consequence, since some species occur in the most varied 
colours. Thus for instance in the strongly burning African Eudia smilaor larvae ha\ T e been obserA T ed with pink 
and blue spots, as also Avith black and red rings, and greenish-yelloAv larvae occur speckled with black, so that 
the colouring of the insect cannot be of any A T ital biological importance. 
The pupae are generally oviform, but by no means uniform. In many species ( Attacus, Actias etc.) 
they appear to be shortened by the abdominal rings being shoved one into another; in Eudia they are flattened. 
In the South-African Gynanisa maja behind the eyes are coniform cephalic points, similar to those in the genus 
Nudaurelia ; in Pseudaphelia apotlinaris, from Cape Colony, there is beside the cephalic points a thorn-shaped 
caudal spike which may be more than 5 mm long. The skin covering the pupae is usually thicker in proportion 
as they are less protected otherwise. The pupae of many species (especially in Africa) lie unprotected in the 
ground, but they have an extremely tough chitinous casing which is as smooth as porcelain and, I presume, 
affords full protection against the ants whose maxillae Avould slip off the smooth covering. On the contrary, 
the coverings of the species spinning cocoons, such as Actias, is not much more solid than soft paper. Webless 
pupae which like the Bunaea are almost like hard nuts to the touch, can also move but slowly and with difficulty, 
whereas the Sarnia, Actias, Saturnia etc. are able to perform quick circular movements with their abdominal 
parts. The fact that larvae and pupae are able to produce a sound ( Phodinia ) has already been reported in 
Vol. II, p. 213. 
The cocoons themselves are of a very different kind and utility. In contrast with the entirely unser¬ 
viceable webs of the Indian Actias, some Antheraea are distinguished by their ability to produce reelable silk. 
Great hopes had been placed on the webs of the $cm?ia-species (Eri-silk) for the production of a coarser, cheaper 
