4 Myr. 
MYRIOPODA. 
in contact, terminally they give off the optic nerves. Below they are 
continued into a mass from which anteriorly spring the antennary nerves, 
posteriorly the oesophageal commissures, and medianly the unpaired 
visceral nerve. 
Von-Ratli (31) describes minutely the histology and nerve supply of 
the sense-organs in the antennae and in the gnathochilarium of the 
Diplopoda. 
Physiology. 
Plateau (29) concludes that the function of the palpi in the Myriopoda 
Chilopoda is to clean the antennae and legs, and to maintain food in the 
mouth in a position most suitable for its mastication by the mandibles. 
The same author (28), after a number of experiments, has decided that 
blind Chilopods can distinguish between light and darkness ; that, 
whether blind or not, it is some time before a change from darkness to 
light is perceived ; that the duration of this time is not greater in blind 
than it is in Myriopods provided with eyes ; that the rapidity with which 
Myriopoda seek concealment is not only due to a wish to avoid the light, 
but is prompted by a desire to bring the whole surface of the body in 
contact with a damp medium. 
The phosphorescence of Geophilus is apparently due to a colourless 
liquid which is excreted from the whole of the ventral surface of the 
body ; Mace (22). 
Ciialande (6) has experimented upon the mechanism of respiration. 
During repose inspiration and expiration are due to movements in the 
respiratory apparatus caused by the contraction of the dorsal vessel, and 
that during activity similar effects are produced by the action of the 
muscles of the body and by the movements of the alimentary canal. 
According to Haase (13), the lip-glands of some Myriopods are of use 
in attachment to smooth surfaces. 
Classification. 
Haase (14) thinks that Scolopendrella stands nearest to the primitive 
Insect. It is distinguished by multiarticulated antennae, three pairs of 
jaws, twelve pairs of legs, and a pair of long caudal appendages in which 
is placed a spinning gland. The abdominal processes are homologous 
with the appendages of the two last pairs of legs in Maclnlis. Attaching 
great importance to these abdominal processes, the author (13) seeks to 
derive from a type resembling Scolopendrella the Myriopoda and Insecta. 
Grassi (10) gives a detailed account of the anatomical relations of the 
same genus. Its affinities with the Pauropoda , Chilopoda , and Diplopoda 
are discussed, and its resemblances with Machilis and Compodea described. 
Schimkiewitch (33) regards Pauropus as an ancestral type, and compares 
the larva of the Chilognatha with that of the A carina. Oudemans (26) 
thinks that the evidence of anatomy is in favour of the view that the 
Myriopoda aud Hexapoda form a natural group. Berlese (1) gives his 
views of the classification of the Chilognatha. 
