The brain as an organ of mind . the acuteness, discriminative power, and structuralelaboration of sense-organs, is almost sure to be greatlyincreased in creatures endowed with such activity; and,looking to the constitution of the Brain as well as tothe nature of the intelligence of these lower animals, itmay easily be conceived that increased sensorial activity is 94 THE NERVOUS SYSTEM OF ARTHROPODS. likely to be associated with greater brain development andwith higher or more complex brain functions. Among the lower Myriapods, such as lulus and Geophi-lus, in wdiich the limbs, though ve
The brain as an organ of mind . the acuteness, discriminative power, and structuralelaboration of sense-organs, is almost sure to be greatlyincreased in creatures endowed with such activity; and,looking to the constitution of the Brain as well as tothe nature of the intelligence of these lower animals, itmay easily be conceived that increased sensorial activity is 94 THE NERVOUS SYSTEM OF ARTHROPODS. likely to be associated with greater brain development andwith higher or more complex brain functions. Among the lower Myriapods, such as lulus and Geophi-lus, in wdiich the limbs, though very numerous, are feebleand ill-developed, the nervous system exhibits only aslight advance over the forms which it presents amongthe higher Annelida. In lulus (fig. 33) the singleabdominal cord shows almost no traces of ganglionicswellings, owing to the great number of the small nervesgiven off on each side, along its entire length, which aredistributed to the hundreds of small segments enteringinto the composition of the Pio 33.—Anterior part of the Nervous System of lulus (Owen), a, a. Cerebralganglia; c, c, optic nerves ; d, d, antcnnal nerves; b, nerves of the paljilessmandibles ; g, oesophageal cords; e, f, stomato-gastric nerves; h, motor nerves tothe maxillse, proceeding from the part wliich corresponds with the sub-oesophagealganglia, here fused with i, i, the ventral cord. The brain (a, a), elongated transversely, is divided by aslight median furrow, and is continuous with the shortand thick optic nerves (c, c). Two separate nervesare received from the antenna) on each side [d, d), below Chap. THE NERVOUS SYSTEM OF ARTHROPODS. 95 and in front of the optic nerves ; whilst nearer the middleline two other nerves on each side (b) are in relationwith the palpless mandibles. The thick oesophagealcords (g) are continued from the posterior and inferiorangles of the brain ; and, as they descend to enter the me-dullary or sub-oesophageal ganglion at the commencemen
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