A zoologist’s perspective on Robert Hooke’s Micrographia (1665) studies of marine and terrestrial invertebrates, and his contemplations on invertebrate “generation” and mutability

Abstract

Nearly half of the “Schemata” (engravings) in Robert Hooke’s seminal work of science Micrographia (1665) show either entire invertebrates or their body parts, and a similar proportion of the “Observations” (descriptions and conjectures) either discuss such organisms at length or refer to them in some other way. Here, taxonomically accurate identifications are attempted for the full array of the book’s marine and terrestrial non-insectan invertebrate taxa (a similar treatment of its insects having recently been published). Those animals belong to the following five phyla: Porifera, Ectoprocta, Nemata, Mollusca, Arthropoda, and to the following species: Flustra foliacea, Turbatrix aceti, Cornu aspersum, Chelifer cancroides, Phauloppia lucorum, Leiobunum rotundum, Tyrophagus longior. Hooke also wrote about a spider which was very probably Salticus scenicus, and he mentions the scabies mite Sarcoptes scabei. The non-insectan invertebrate Observations are examined with a view to evaluating their scientific content, originality and insightfulness. I show Hooke to have undertaken pioneering comparative studies with regard to structure and behaviour. Though brief, his conjecture on swimming in nematode worms is among the earliest attempts to explain the physics of swimming, pre-dating that of Giovanni Borelli. Hooke’s writings on the generation of non-insectan invertebrates are analysed in detail and placed into context with those he made on other organisms. He postulated an explicitly reproductive scenario for the generation of gall-associated arthropods, and he had doubts about the supposedly spontaneous generation of mites and insects associated with “putrifying” or “fermenting” substrates. Drawing upon a substantial body of evidence gleaned from the text of Micrographia, I argue that his greater awareness of the reproductive biology of arthropods was a particularly important driver of those ideas. I also analyse Hooke’s writings on the mutability of mites, and I suggest that they informed his later Discourses of Earthquakes conjectures concerning intra-specific variation and the production of new forms.

Keywords:

• early science
• invertebrates
• spontaneous generation
• mutability

Acknowledgements

Thanks go to the following individuals who provided valuable information, advice, technical support or encouragement: Paulo Arratia, Paul Erdös, Diego Gutiérrez Gregoric, Bruce Halliday, George Jervis, Julia Jervis, William Jervis, Bob Jones, Adriano Kury, David Lloyd, Mark Maraun, John Morgan, Jim Nishiura, Roy Norton, Guenther Raspotnig, Paul Richards, Jeffrey Schulz, Henk Siepel, Mike Taylor and David Walter. I am also grateful to the many historians whose writings on Hooke and early science inspired me to delve deep into Micrographia. Lastly, I am indebted to Matthew Cobb for his very useful comments on the originally submitted version of this paper.