Genre:

Essay

Relevant illustrations:

eng. [10]

Subjects:

Comparative Anatomy, Oceanography, Natural History, Ornithology, Animal Behaviour, Engineering, Taxonomy, Functionalism

    Suggests that 'Among the many curious analogies born of modern investigation, none are more interesting than those showing striking cases of parallelism in the habits and customs of animals whose environments are totally dissimilar', and observes that the 'ocean bed seems peopled with forms so resembling those of land that a modification of structure to conform with their surroundings alone appears to be the point of difference'. Indeed, the 'resemblance between the creatures of land and sea is extremely striking' (98), especially those in 'gayly bedecked fishes [...] in all their motions reminding us of the birds of the shore', such as the 'gorgeous parrot-fishes [which] are the sun-birds of the sea' and the 'more [...] modest' fishes of 'our colder waters of the North, [that] call to mind the robin and the thrush, those welcome harbingers of spring'. Many of these fish, moreover, are 'nest-builders, erecting structures as complicated as those of the birds, and equalling them in design and finish'. (99) Describes the construction of several of these aquatic nests, noting in the case of the 'lamprey-eel (Petromyzon marinus)' that 'when stones that weigh several pounds are to be brought, they adopt tactics worthy of an engineer' and drag them down stream with their 'sucking mouth'. Also comments that the young of the lamprey-eel 'possess so many characteristics to distinguish them from the adult form that for a long time they were considered distinct animals, and the young described as a different genus (Ammocœtes)'. (103) Reports that in an 'area of 260,000 miles, popularly denominated the Sargasso Sea, are found numbers of animals that seem peculiarly adapted by various modifications to the pelagic life they lead', including the 'soft shelless mollusk Scyllæa' and the 'short-tailed crab Nautilograptus' which 'have assumed the exact tint of the surrounding weed—a protective resemblance that serves them well' (105). Relates how 'in the Orinoco is found the perai, whose nest, in strange analogy to that of some birds, hangs pendent from some overhanging branch, drifting in the tide, a veritable garden of aquatic plants and clinging vines', and also suggests that 'one of the most remarkable examples of jumping and land-visiting fishes is seen in Periophthalmus' which 'leaves the water and seeks the shore—in quest of food, perhaps; or, as it seems at times, for the mere pleasure of a change' (107).