This is Hydrophilus piceus – ‘The Great Water-Beetle’. Of those beetles native to the UK it is second in size only to the stag beetle. What is more, it is the only insect to have been modelled by Friedrich Ziegler. While human embryology has tended to be the source of interest for those that come to the Ziegler models, it is always useful to bear in mind the wide variety of subjects in which these models were considered useful. What then was special about this beetle, and why does Leeds have a complete collection of the 34th Ziegler series?
Firstly, it is an ideal organism for the study of development. Not only does the beetle have a thoroughly interesting life cycle (including the building of a nest upon the surface of a pool of water) but includes moments in which one can see straight through its exoskeleton. This is possible after it sheds its skin, which occurs no-less than three times.
Secondly, it is cheap to maintain and can be grown easily in laboratory aquaria. Indeed in Britain, the homeland of aquarium keeping, they were commonly kept by amateurs and (if you couldn’t be bothered to catch one yourself) could be bought for the very reasonable price of 1 shilling.
Finally, in their early stages of growth, they are very very small indeed. For the study of this aspect of its development therefore, you would need a microscope, and preferably a series of Ziegler models with which to work.
Towards the end of the nineteenth century, microscopy was beginning to enter into the disciplines of zoology and botany. In Leeds a very early advocate was Louis Compton Miall (1842-1921), who introduced a course on practical biology to, what was then the Yorkshire College of Science, in 1894. This was before the department had even built its own laboratory. Samuel Alberti has described how such rooms were by no means pleasant places to work. Here he quotes a student from the early 1900s:
“the atmosphere is even more polluted & tainted than that of the Chemical Department…At the far end of the room are stationed mysterious jars evolving a strange & unpleasant odour, giving a decidedly fish-markety aroma to the place.”
While most of the messiest work would be done through dissection, Alberti has highlighted that microscopy was increasingly coming to dominate biological instruction. Miall was insistent upon each student becoming at least competent in the skills necessary for the preparation of slides and the ability to understand precisely what one was seeing. It was here that Ziegler’s models would have been of the most use. An excellent picture of the this kind of laboratory work, taken at Manchester (which can be found in Nick Hopwood’s ‘Embryos in Wax‘), demonstrates how each student would have access to these models, while carrying out their own microscopic analysis. Hydrophilus piceus would have been particularly important to the students at Leeds as Miall was widely acknowledged as one of the worlds foremost experts upon aquatic insects, publishing a book on the subject in 1895. You can read it here for free! Unfortunately the students in the picture at Manchester are busily working away at something other than insects, which in a round about way returns me to my original point.
It is usually the amphibian, reptilian, mammalian and of course human embryological models that receive the most attention in displays of Ziegler models. In choosing to display Hydrophilus piceus we are both recognising the history of the development of biology at Leeds and ensuring that as much as possible of the variety to be found in Ziegler is available to the public. To my knowledge the only other permanent display of such models in the UK can be found at Cambridge’s Whipple Museum of the History of Science. Other large collections can be found at the University of Aberdeen, the Royal College of Surgeons of Edinburgh and the University of Dundee, while some examples are also held at the University of Birmingham. Finally, a few years ago the Wellcome Collection produced an exhibition surrounding the history of anatomy which included some Ziegler models. A video of the exhibition, which focusses upon the earliest examples of wax modelling, can be found below.
That’s everything for now, though this post is a work in progress. If you know of any other exhibitions focussing upon Ziegler in the UK, or have any recommendations for this post, please let me know in the comments section.