The history of creation, or, The development of the earth and its inhabitants by the action of natural causes : a popular exposition of the doctrine of evolution in general, and of that of Darwin, Goethe and Lamarck in particular / from the German of Ernst Haeckel ; the translation revised by E. Ray Lankester.

Date:
1876
Catalogue details

Licence: Public Domain Mark

Credit: The history of creation, or, The development of the earth and its inhabitants by the action of natural causes : a popular exposition of the doctrine of evolution in general, and of that of Darwin, Goethe and Lamarck in particular / from the German of Ernst Haeckel ; the translation revised by E. Ray Lankester. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    stalk (cui^viiig' upwards in oui* drawing) ; by means of it the Barnacle crab grows on rocks, ships, etc. On the ventral side are six pairs of feet. Every foot is forked and divided into two long, curved, or curled tendrils furnished with bristles. Above and behind the last pair of feet projects the thin cylin- drical tail. Fig. E c represents a parasitic sack-crab (Sacculina purpurea), from the order of Root-crabs (Rhizocephala). These parasites, by adaptation to a parasitical life, have developed out of Barnacle crabs (Fig. D c), much in the same way as the fish-lice (C c), out of the freely swimming Oar-legged crabs (B c). However, the suppression, and the subsequent degeneration, of all of the organs, has gone much further in the present case than in most of the fish-lice. Out of the articulated crab, possessing legs, intestine, and eye, and which in an early stage as nauplius {E Plate YIII.), swam about freely, there has developed a formless, unsegmented sack, a red sausage, which now only contains sexual organs (eggs and sperm) and an intestinal rudiment. The legs and the eye have completely disappeared. At the posterior end is the opening of the genitals. From the mouth grows a thick bunch of numerous tree-shaped and branching root-like fibres. These spread themselves out (like the roots of a plant in the ground) in the soft hinder part of the body of the hermit- crab (Pagurus), upon which the root-crab lives as a parasite, and from which it draws its nourishment. Our drawing (E c), a copy of Fritz Miiller's, is slightly enlarged, and shows the whole of the sausage-shaped sack-crab, with all its root-fibres, when drawn out of the body upon which it lives. Fig. c is a shrimp (Peneus Miilleri), from the order of ten-foot crabs (Decapoda), to which our river cray-fish, and its nearest relative, the lobster, and the short-tailed shore-crabs also belong. This order contains the largest and, gastronomically, the most im- portant crabs, and belongs, together with the mouth-legged and split-legged crabs, to the legion of the stalk-eyed mailed crabs (Podophthalma). The shrimp, as well as the river crab, has in front, on each side below the eye, two long feelers (the first