. The brain as an organ of mind. Brain; Thought and thinking; Brain. Chap. VI.] NERVOUS SYSTEM OF ARTHROPODS. 99 there are general similarities in the external configuration of the body. Thus in Scorpions the arrangement of the nervous system is not very dissimilar from that met with in the Prawn and its allies. The thoracic ganglia have coalesced with one another and with the anterior abdominal ganglia; thereby forming a large stellate ner- vous mass which supplies the limbs and the anterior part of the abdomen. The ventral cord throughout the remainder of the abdomen, and its caudal prolonga
. The brain as an organ of mind. Brain; Thought and thinking; Brain. Chap. VI.] NERVOUS SYSTEM OF ARTHROPODS. 99 there are general similarities in the external configuration of the body. Thus in Scorpions the arrangement of the nervous system is not very dissimilar from that met with in the Prawn and its allies. The thoracic ganglia have coalesced with one another and with the anterior abdominal ganglia; thereby forming a large stellate ner- vous mass which supplies the limbs and the anterior part of the abdomen. The ventral cord throughout the remainder of the abdomen, and its caudal prolongation, is marked at intervals by a series of small ganglionic swellings. In Spiders proper, the nerA'ous system attains its maxi- mum amount of concentration. The bilobed brain (fig. 37, c) receives nerves on each side (o), corresponding in number with the ocelH which the animal may hajDpen to Fig. 37.—Head and Nervous System of a Spider [Mugale). (Owen after Dugfes.) c, Cerebral ganglia (side view), receiving (o) optic nerves, and (m) nerves (sensory and motor) from the powerful mandibles, vi'. The cerebral ganglia are connected by very short oesophageal cords with a large stellate ventral ganglion (s), from which five large nerves issue on each side (p, I, I); a, mouth; b, oesophagus ; d, stomach. It also receives tw^o large nerves (m), which probably con- tain outgoing as well as ingoing fibres, from the so-called mandibles (?;i''). Omng to the suctorial habits of these fierce and predatory creatures, the oesophagus is very narrow; and as a consequence, the oesophageal cords are very short, so that the brain is—unlike the arrangement which obtains. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Bastian, H. Charlton. N. Y. , Appleton
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