To get an idea of the kind of mounted material Lowne would have been working from, I dug out a contemporary slide of the blowfly tongue by noted Victorian slide mounter Charles Morgan Topping. I located the same area on the slide and and took a single image in the focal plane of the (pre)stomal teeth. The microscope is a Nikon Diaphot with LWD 0.52 phase/DIC condenser. The camera was a Canon 40D front mounted at the microscope SLR port and there is an in-microscope X2.5 magnification factor. The objective used was a Zeiss X25 0.65 planapochromat in conjunction with the Nikon X40 DIC prism.
To put this focal plane in context I also made a short stack of 11 images, which place the (pre)stomal teeth better in relation to the pseudo-tracheae and this corresponds quite nicely with Lowne's illustration.
For orientation of this area on the whole mount of the blowfly tongue, here is a large stitch of 100 or so images of the mount from which the previous two detailed images are taken. This was taken with a Nikon X10 0.25 Plan DIC objective using the same microscope setup last year. The area of the proboscis in question is roughly outlined by the red box.
It is fascinating to see how much more information would have been available to Lowne if modern stacking techniques had been available to him. He would be astonished to see what is possible now, but equally it is remarkable what he achieved with the equipment available to him.
