It is often said that a picture is worth a thousand words. We use both drawings and photos (and sometimes even films) when we are describing species, and without these illustrations, we would often have to make guesses as to what the author meant when describing the morphology of the species in interest.
Generally, the old literature did not make as much room for illustrations as we have the possibility to do today – the printing often needed entire plates (pages) produced much in the same way an artist still produces a carved or engraved print today – and when there is a plate in an old publication it quite often is a piece of art. But – the plates (figure-pages) were expensive to print (even more than the text-pages), and thus often limited to the bare necessities.
There are exceptions! C. Spence Bate and J. O. Westwood (both with so many letters behind their names that they included “etc” at the front page) commissioned J van Voorst in London to print their book “ A History of the British Sessile-Eyed Crustacea” in two volumes. The first came in 1863, the second in 1868.
And it is enjoyable reading. “Sessile-eyed” crustaceans are explained as those crustaceans who do not have stalked eyes (as for instance the crabs and shrimp have) and it was used to classify crustaceans since Leach in 1814 named the gruop “Edriophthalma” (sessile-eyed in greek). This group included Isopods and Amphipods – but the discussion was still going strong about what taxa should be included in these groups, and how they were “connected” with the other crustaceans. The gentlemen Bate and Westwood decided to describe and discuss each of the species they knew of as sessile-eyed in Britain. This would be a basis for the further discussions on higher groupings. Interspersed in the text are figures of the species and special morphological structures they are discussing, making the book easy to follow and understand. An introduction on the general morphology, physiology, reproductive biology and geographical distribution of the sessile-eyed crustaceans, the rest of part 1 discusses the Amphipoda.
They really mention every species they have come across – ever – from anywhere in Britain. Sometimes that may be one single specimen of what they think must be a new genus and species (and that seems to have been forgotten later), and in addition to the drawings of the morphology they add a drawing of the location where it was found.
It is at the end of volume 1 that we come to the picture that captures my imagination the most. Under the discussion of Corophium longicorne (accepted name: Corophium volutator) they discuss the extraordinary strong second antennae of the species:
“The inferior antennas are very powerful, and in the male are longer than the animal itself; the pentultimate joint of the peduncle being armed upon the inferior distal extremity with a strong tooth, which appears to assist considerably in holding any object when the extremity of the antennae is folded upon itself; this organ appearing to possess the strongest prehensile power, and being no doubt used as a weapon of offence in its battles with other animals in its struggle for existence.”
Corophium are known from sandy and muddy shores – where they “dwell in small tubular galleries, excavated in the mud, over which the tide flows and ebbs”. They go on to discuss their ecology – as predators of other shore-living invertebrates.
They cite “Rambles of a Naturalist” of Quaterfages on the feeding habits of this fierce amphipod:
“at about the end of April they come from the open sea in myriads (they are called Pernis by the fishermen of the coast of Saintoge) to wage war with the annelids, which they entirely destroy before the end of May; they then attack the mollusca and fish all through summer, and disappear in a single night about the end of October, and return again the following year.”
Bate and Westwood do not follow up the story from Quaterfages with any other documentation, but they ask their readers to send them more data if they have. Corophium volutator was described already in 1766 by Pallas, and is found on sandy or muddy beaches all around the North Sea. Maybe you will see a battle between a Corophium and an annelid? All later research into this species and the close group of related amphipods show us that these are detrivorous (eating organic matter from the mud where it lives). We might never know what inspired the fishermen that Quaterfages talked to. But if you see something like this, we would really like to know!
Bate CS, Westwood JO.1863. A history of the British Sessile-Eyed Crustacea. Part 1. John van Voorst, London (Paternoster Row). 580 pp.