Lectures on the comparative anatomy and physiology of the invertebrate animals : delivered at the Royal College of Surgeons . line on the under side ofthe carina. § The cirrigerous arms in all the Cirripeds have powerfulmuscles for their actions, which are of the utmost importance to theanimal, inasmuch as the food is obtained by the currents which they123 produce, and almost incessantly maintain, in ? the surrounding water. The sessile Barna- cles are provided with a series of musclesattached to the margin of the conical shell,which act on the opercular calcareous pieces,and close the opening
Lectures on the comparative anatomy and physiology of the invertebrate animals : delivered at the Royal College of Surgeons . line on the under side ofthe carina. § The cirrigerous arms in all the Cirripeds have powerfulmuscles for their actions, which are of the utmost importance to theanimal, inasmuch as the food is obtained by the currents which they123 produce, and almost incessantly maintain, in ? the surrounding water. The sessile Barna- cles are provided with a series of musclesattached to the margin of the conical shell,which act on the opercular calcareous pieces,and close the opening of the shell. The nervous system {Jig> 123), first de-scribed and figured by Cuvier in the Lepasanatifera^ presents the homogangliate oesophagus is surrounded by a wideoral ring, closed above by a pair of super-oesophageal ganglions, which send off nervesto the peduncle, the ovaria, and to theaborted and confluent eyes. Mr. Darwin^ \J/ lias detected a small ganglion on each op- tic nerve in the Lepas fascicular is. ^ * CCXXIII. p. 30. t lb. p. 33. % Prep. Nos. 62, 68, 69. § CCXXIII. p. 33, II lb. p. % Nervous System. Lepas. CIRRIPEDIA. 281 The ring is completed below by tbe large suboesophageal ganglion,which gives off the nerves to the trophi, the first pair of cirri-gerous feet, and the adjacent muscles. The second thoracic gan-glion supplies the second pair of feet; the third ganglion supplies thethird pair of feet; the fourth and fifth pairs of ganglions are approxi-mated to each other; and the tubular extensile tail or penis receivesthe two last pairs of nerves. Two branches from the oesophagealring pass to a small ganglion on either side of the stomach, fromwhich the alimentary canal is supplied. The nervous system is thatpart of the organisation of the mature animal which most unequivo-cally indicates the province of the Animal Kingdom to which theclass Cirripedia belongs; and it indicates their superiority to theAnellids, and their closer affinity to
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Keywords: ., bookauthorowenrichard18041892, bookcentury1800, bookdecade1850
