. Text book of zoology. Zoology. Fig. Fig. 147. The last four joints of an arthropod limb with their muscles: diagrammatic. I articulation, B and 6 flexors, 8 and s extensors, u. places where two joints touch one another, and the articular membrane is very narrow; 1 terminal, 2 penultimate joint, etc. —Orig. Fig. 148. Longitudinal section through a j o i n t of an Arthropod : diagrammatic. c cuticle, ep epidermis, I articular membrane, M muscle, o opening of the tendon to which the muscle is attached.—Orig. The nervous system agrees closely with that of the Annelids. Just as in these ani
. Text book of zoology. Zoology. Fig. Fig. 147. The last four joints of an arthropod limb with their muscles: diagrammatic. I articulation, B and 6 flexors, 8 and s extensors, u. places where two joints touch one another, and the articular membrane is very narrow; 1 terminal, 2 penultimate joint, etc. —Orig. Fig. 148. Longitudinal section through a j o i n t of an Arthropod : diagrammatic. c cuticle, ep epidermis, I articular membrane, M muscle, o opening of the tendon to which the muscle is attached.—Orig. The nervous system agrees closely with that of the Annelids. Just as in these animals there is a pair of ventral ganglia in each segment, connected with those of the adjacent segments by a double nerve cord. Prom the most anterior of these ganglia spring two nerve cords, which run round the oesophagus to unite with a paired ganglion mass, the cerebral ganglion, lying in the head. This often attains to a very considerable size, which is correlated, amongst other things, with the development of certain sense organs, situate on the head, the compound eyes. The ventral ganglia often exhibit remarkable differences from those of the Annelids, differences which are due to the above-mentioned dissimilarity in the formation of the segments and their grouping into different regions. In well-developed segments for example the ganglia are large, whilst a fusion of many segments is accompanied by a fusion of their ganglia. In some 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 Boas, J. E. V. (Johan Erik Vesti), 1855-1935; Boas, J. E. V. (Johan Erik Vesti), 1855-1935. Lehrbuch der Zoologie. London, Sampson Low, Marston
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1896
