2 12 
MILLIPEDES. 
The suborder Polydesmoidea is almost as extensive as the luloidea, its members 
being spread over the habitable world. The largest species belonging to the genus 
Platyrrhaclius, which reach a length of several inches, occur in Tropical America 
and the East Indies. In all, the number of segments is nineteen or twenty, or the 
fewest amongst the Helminthomorpha. Eyes are wanting, and, as in the luloidea, 
the segments form solid rings, owing to the fusion of the pleurse and pedal laminse 
with the terga. Secret¬ 
ing pores are generally 
present on most of the 
segments, though some¬ 
times absent in members 
of the family Cryptodes- 
midce. When present, 
they are almost always 
borne upon large plate¬ 
like processes, springing 
from the sides of the 
segments. In distribu¬ 
tion this suborder is 
cosmopolitan, the temperate forms being of small size, while some of the tropical 
species are large and beautifully coloured. 
In habits all millipedes seem to be very similar. Although mostly 
vegetarians, feeding on soft roots, fruits, and succulent plants, one of the smaller 
kinds of Iulidoe eats worms and decaying animal matter. They occur under 
stones, logs of wood, or in rotten tree trunks in damp places; and in tropical 
countries come out in numbers after rain, when they may be seen crawling over 
the ground and climbing bushes. Moisture is necessary for their existence, and in 
captivity they freely drink water or milk. Most are slow in their movements, and 
never trust in speed to escape. When walking the body is kept fully extended, and 
propelled by the legs, the movements of which resemble a series of waves passing 
up the body from behind forwards. As already stated, many forms are devoid of 
eyes; but even those possessing well-developed visual organs appear scarcely able to 
do more than distinguish light from darkness. As they crawl along, every inch 
of the road is first carefully touched by the antennae, which are tipped with a 
sensory organ, and the creatures appear to be unaware of the presence of an 
obstacle until the antennae have actually come into contact with it. All millipedes 
are perfectly harmless, and may be handled with impunity; but those species 
possessing odoriferous glands emit a disagreeable odour, due to the secretion of a 
fluid containing prussic acid. This, no doubt, serves as a protection against birds, 
ants, etc., to these otherwise defenceless creatures. Some birds will, however, eat 
them ; and in a hornbill’s nest in the British Museum the plaster used to block the 
entrance is largely composed of crushed fragments of a large Spirostreptus. Many 
of the species which have no glands are otherwise protected. Polyxenus, for instance, 
is studded with bristles; while the Oniscomorpha roll themselves up into a round 
ball, with nothing but the horny integuments exposed. In the breeding-season the 
females of several forms make earthen nests for their eggs, working the lumps 
flat millipede, Polydesmus comjolanatus (much enlarged). 
