ARTEVELDE, Philip van, son of the above, lived in
retirement till 1381. Some years before that date enmity
had again arisen between Count Louis of Flanders and the
somewhat turbulent citizens of Ghent, who, under one
Hyons, had exp lied the count s adherents, plundered his
house, and slain several of his officers. Hyons died in
1379, and in 1381 the citizens^ under Peter van der
Bosch (Dubois), were closely blockaded by the count. In
this emergency Van der Bosch proposed that the son of
the great Artevelde should be invited to take the direction
of affairs, Philip accepted, at once entered on public life,
and by some strong measures secured his power. The
inhabitants of Bruges had at this time allied themselves
with the count, and Artevelde resolved to punish them.
He led out his forces quietly, and utterly defeated the army
of the count, who escaped with difficulty. Bruges was
plundered, and submitted to Artevelde. Next year the
French, taking up the cause of Louis, invaded Flanders,
and at Rosbecque completely routed the forces of Ghent.
Many thousands were slain, and among them Artevelde
himself. The brief but stirring life of this popular leader
is admirably treated in Sir Henry Taylor's drama, Philip van Artevelde.
ARTHROPODA. The
Aristotelian distinction of
Malacostraca, or
Crustaceans, and
Entoma, or
Insects, has been referred to by
Agassiz as in reality more precise than
Linnæus's last classification (1766), in which his
Crustaceans form part of the Apterous group of
insects. But whereas the Greek naturalist recognised the notchings which indicate
annuli,
somites, or body-rings, in
Coleoptera and the other groups to which the class-name
Insect is now restricted, and in
Worms, under which he comprehended
insect larvæ, several true
Annelids, and
intestinal worms (
Scolecida), he failed to appreciate this as a feature common to the
Malacostraca or
Scleroderma, which he named on account of the character of their integument.
Linnæus, on the other hand, saw that annulation was the most prominent common feature, and his
Insecta, therefore, were a good natural group so long as embryology could throw no light on the affinities of the
Cirripeds and
parasitic Crustaceans—these two groups forming, together with the
intestinal worms,
molluscs,
zoophytes, and
lithophytes, the
class Vermes.
Cuvier (1829) includes in the third branch of his scheme,
Animalia articulata,
Annelids,
Crustaceans,
Arachnids, and
Insects (the
Myriapods being an order of this class).
Latreille (1796) proposed a scheme in which the orders of the
Insects (as now restricted) formed equivalent groups with the
Crustaceans,
Arachnids, and
Myriapods, which now first appear as a distinct group, though still united with a section of the
Crustaceans.
Latreille further, in 1801, recognised the
Cirripeds as intermediate between his
Insecta and the
Molluscs.
Lamarck gave the value of
classes to the
Insects, the
Arachnids (including therein the
Thysanura and
Myriapoda), the
Crustaceans, and the
Cirripeds. But he has no province answering to the
Cuvierian Articulata, since these
orders are, with
Annelids,
Conchifers (=
Lamellibranchs), and
Molluscs (=
Odontophora),members of the “sensitive
animals,” the
Lernæans and other
parasitic Crustaceans being an
order of the
Vermes, and therefore apathetic
animals.
De Blainville, still relying chiefly on external form, recognises four types in the sub-
kingdom of the bilateral
animals:—(
Artiomorpha or
Artiozoaria), of which the first is
Osteozoaria (
Vertebrates). The second,
Entomozoaria (
Articulates), includes:
Class 1.
Hexapoda,
Insecta proprie sic dicta; 2.
Octopoda,
Arachnida; 3.
Decapoda,
Crustacea decapoda and
Limulus; 4.
Heteropoda,
Squilla,
Entomostraca,
Epizoa; 5.
Tetradeoapoda,
Amphipoda and
Isopoda; 6.
Myriapoda; 7.
Chætopoda,
Annelides; 8.
Apoda,
Hirudo,
Cestoidea,
Ascaris. The third type,
Malentozoaria, is intermediate between the
Articulates and
Molluscs, and embraces two
classes:
Nematopoda,
Cirripeds; and
Polyplaxiphora, the
Chitons. The classification of which this forms a part is a compromise between the method of
Cuvier, based on the recognition of distinct plans, and that of
Ehrenberg, who sketched each group as departing from the common plan of the
animal kingdom only by excess of development in one or other direction. The
Articulata,
viz.,
Insecta,
,
Crustacea (the
Cirripeds and
Epizoa being included),
Annulata, and
Somatotoma (the two latter making up all that are now known as
Annelids), he distinguished from
Molluscs by the isolation of their
ganglia and their succession, those of the
Molluscs being dispersed.
Owen's
Homogangliata, as equivalent to
Articulata, is the expression of the same difference; his
Insecta embrace two sub-
orders,
Myriapoda and
Hexapoda, and the
Annellata are placed between the
Epizoa and
Cirripeds.
Milne-Edwards (1855) divides the
Entomozoaria or
Annellata into two groups,—(1.)
Arthropoda, including
Insects,
Myriapods,
Arachnids, and
Crustaceans; and (2.)
Vermes, including
Annelids,
Helminths,
Turbellarians,
Cestodes, and
Rotifers.
Siebold and
Stannius (1845) made the Arthropods a primary division co-ordinate with
Vermes, and united the
Myriapods with the
Crustaceans.
Leuckart's
Arthropoda comprise two
classes,
Crustacea and
Insecta; the latter combining the
orders,
Myriapoda,
Arachnida, and
{{lang|la|Hexapoda.
Fitzinger's
Arthrozoa, or eminently motor
animals,
Crustaceans,
Arachnoids, and
Insects, contrast with the
Dermatozoa or
Molluscs, which are eminently sensitive.
Von Baer's
Articulata correspond to the
Cuvierian group under the same designation, and like it represent a type of organisation, the longitudinal or bilaterally symmetrical, the organs being arranged with reference to the axial
alimentary canal. The
embryological system of
Van Beneden (1855) rests upon the position of the
vitellus relatively to the surface of the
embryo, the
Articulates being designated by him
Epicotyledones or
Epivitellians, the
vitellus being received into the
embryo on the dorsal or upper surface, while the
vertebrates receive the
yelk on the ventral or lower surface, and are therefore
Hypocotyledones or
Hypovitellians. As will be pointed out afterwards, this nomenclature is unfortunate, since the surfaces thus contrasted are identical, both being
the hæmal aspects of the body. It may further be remarked that the term
Articulata is manifestly one which should be abandoned, since it is made to represent very different things, being used by
Cuvier,
Ehrenberg, and
Owen to include the
Annelids,—by
Van Beneden,
Vogt, and some more recent writers, to their exclusion. Neither is
Arthrozoa, the
Greek equivalent of
Articulata, more commendable,
Burmeister and
Fitzinger using it with the same difference. But
Arthropoda has varied only in the rank assigned to it, not in the area it represents; thus
Milne-Edwards makes it a sub-division of the
Annellata;
Van Beneden,
Siebold and
Stannius, and
Leuckart, a primary division of the
animal kingdom. But as a general designation for those
animals which are made up of nearly equivalent
somatomes or
somites is needed,
Macleay's term
Annulosa is, perhaps, the best, since it has never been used for two incommensurate groups.
Leach, and later (1825)
Latreille, proposed
Condylopoda as the name of the group for which
Arthropoda was afterwards devised. Custom has overborne the rule of priority, and the later is now the more common name. The classifications hitherto mentioned rest solely on an anatomical basis, those of
Von Baer and
Van Beneden deal-