Tuesday, December 22, 2015

Uninvited house guests

The rain might be lashing down outside but there's still plenty of wildlife to track down much closer to home. Unless your house is hermetically sealed and doused in deadly chemical cleaning agents, any or all of these could be lurking in the shadows.

If you settle down to read a good book and the punctuation seems to be moving around, then you could be looking at one of these tiny booklice. They are not much bigger that a full stop and feed on fungi that grow on damp paper, and also eat the glue that holds the pages together. Old damp paperbacks are prime habitat but they also like nothing better that feeding on wallpaper paste behind loose wallpaper. If your wallpaper makes clicking noises, it may be because they are headbutting it during their courtship.

Silverfish. You might have these most ancient of insects, that move like greased lightning, in a damp corner of a kitchen cupboard where they like to feed on starchy foods like flour.

Silverfish Lepisma saccharina are covered in tiny scales that rub-off easily, making it easier for them to wriggle out of the grip of a predator - which might go some way to explaining why they've been around for 400 million years.

This is the firebrat, the silverfish's larger and hairier cousin. It likes warmer conditions and used to be common in bakeries. Give yourself a pat on the back if you provide a home for these - they are not very common.

And finally, the daddy long-legs spider Pholcus phalangioides. Whatever you do, don't throw these out of the house as they can't survive anywhere else. They are humans' constant companions, only ever found inside our homes and outbuildings in our northern latitudes. They are useful to have around, preying on other household invertebrates - even on the fearsome house spider that comes into our homes during cold weather. This daddy long-legs spider is showing her maternal instincts by carrying her eggs around in her jaws.

Wednesday, December 16, 2015

The man who turned down the job of naturalist on HMS Beagle

On August 13th. 1831 Reverend  John Stevens Henslow, Professor of Botany at the University of Cambridge, received a letter asking him to recommend a suitable gentleman ship’s naturalist to accompany Robert Fitzroy, Captain of HMS Beagle, on a circumnavigation of the world.

Henslow, the finest field botanist of his day, would have been the prime candidate but family responsibilities stood in his way. His next thought was to nominate his brother-in-law, Reverend Leonard Jenyns but he declined in favour of tending to the spiritual needs of his parishioners.

So by the end of August Henslow had offered the job to Charles Darwin, his student protégé at Cambridge. The rest is (natural) history.

But what if Henslow, a creationist until the day he died in 1861, or his cleric brother-in-law Leonard Jenyns, had sailed with Fitzroy? It seems unlikely that they would have come up with a theory of evolution. If Charles Darwin’s date with destiny had never arrived it would have been left to some other scientist, in another place and at another time, to provide the theory that underpins all of modern biological science. 

But Jenyns, in his own way, made a lasting contribution to science too – a contribution that is very relevant to the turbulent climatic times that we live in.

It can be found in this little book, A Naturalist’s Calendar, published in 1907 and edited by Francis Darwin, Charles Darwin’s son.

Stay-at-home Jenyns, who by this time had changed his name to Leonard Blomefield in order to claim an inheritance, was curate of Swaffham Bulbeck in Cambridgeshire from 1823 to 1849 and during that period kept detailed phenological records of natural events in his parish. While Charles Darwin, whom remained a life-long friend, was pondering on Galapagos finches and giant tortoises, Jenyns was recording the annual date when local frogs spawned or primroses bloomed.

Phenology, the study of the timing of natural events, is an important science today because observing the changes in ways in which the life cycles of plants and animals respond to climate provides some of the best evidence that the climate really is changing. Jenyns’ meticulous records, for scores of familiar plants and animals, record the earliest and latest dates of phenological events and also the mean dates. They provide a reliable datum point for comparisons in today’s warmer world.

Nature's Calendar the citizen science phenology web site where we can all monitor the natural changes brought about by climate change, is a modern day manifestation of Jenyns' work.

When Jenyns made his observations it must have seemed like a simple pastime for a parson-naturalist with time on his hands – the kind of observational recording that is often today sneered at by experimental scientists. As it has turned out, the results of his curiosity and dedicated recording have become highly relevant to our modern predicament.

I’m typing this on a mid-December evening when the temperate outside is warmer than many a spring day, after one of the warmest Novembers on record. I wonder what Jenyns would have made of that. 

Monday, December 14, 2015

Vere Lucy Temple (1889-1981): a forgotten, gifted entomologist and illustrator

These very attractive plates are from a book called Butterflies and Moths of Britain, written and illustrated by Vere Lucy Temple and published in 1945. 

I bought a copy in a second-hand bookshop about fifty years ago and have always liked the way that the plates were drawn, with the coloured butterflies portrayed against line drawings of their food plants, usually with the larvae and pupae.

It's difficult to find much information about Temple, who was born in 1898 and is thought to have died in 1981. She specialised in natural history and animal painting and seems to have been in demand in the 1920s and 1930s, when she exhibited in leading galleries.

She wrote and illustrated seven books and illustrated five others. All her original work seems to have been auctioned in numerous lots after her death. On the strength of these attractive butterfly and moth illustrations, she deserves to be more widely known. 

Vere Lucy Temple was a Fellow of the Royal Entomology Society, which explains why the text of her book is so full of perceptive detail, but it's also a very lively, personal and engaging account that conveys her passion for butterflies. 

In her preface she acknowledges help and advice from several eminent lepidopterists and scientists of her day and also refers to what was, then, cutting-edge research on insect vision and behaviour.

Thursday, December 10, 2015

Waxing lyrical about dung fungi

After a lifetime as a professional scientist, I have to admit that scientific research papers constitute one of the most tedious forms of literature ever devised. The science might be exciting but the words are usually unspeakably dull. That isn't just my opinion .... here's what Nobel laureate James Watson, discoverer of the structure of the DNA molecule, had to say about the matter:

“There is no form of prose more difficult to understand and more tedious to read than the average scientific paper”.

Francis Crick. 1994. The Astonishing Hypothesis

But it wasn't always this way.

This is a line illustration of the dung fungus Pilobolus, taken from this research paper:

W.B. Grove (1884) On the Pilobolidae, with a synopsis of the European species, and a description of a new one. Paper read at a meeting of the Birmingham Natural History and Microscopical society, 17th. April 1883.

They say a picture is worth a thousand words, but in this case I much prefer a thousand words because I have never read a scientific publication that so vividly conveys the author's sheer delight at a discovery. 

Here is his description of the fungus (bear in mind that in Grove's day scientific papers like this were routinely read aloud to an audience. For fullest effect stand tall, preferably in evening dress, and read it aloud while grasping your lapels or making extravagant gestures. Reading scientific papers was performance art in those days)

"Imagine an oval translucent vase of exquisite outline, carved from a single diamond, not indeed of the finest water, but brought from South African Fields, tinged with a delicate yellow colour. Place beneath this a gracefully curved slender stem, of crystal clear, and where they join let a circlet of the purest gold lie coiled within the tube. Then let a beautiful and limpid light radiate from every part. To enhance its effect, take a piece of blackest jet, shaped into a perfect hemisphere. Polish its surface until it shines like a Venetian mirror, and gently poise this sooty crown over the mouth of the transparent vase. Let glistening strings of orient pearls hang around in graceful festoons, and imagine the whole of this priceless work reduced in size till the total height exceeds not a twentieth of an inch. To complete the contrast, thickly strew these fairy jewels over the half-dried surface of a cake of cow dung, and you have imitated nature as far as your powers allow. To mortals this treasure is known by the name Pilobolus, and the particular species I have pictured is called Pilobolus kleinii."

Click here for a movie of Pilobolus and click here for a photograph and information and you'll see why he found it so beautiful.

W.B.Grove wasn't just a describer of nature - he was an experimentalist, gifted with curiosity too. Here's what he did next.

"Once, when I was examining a tuft with a lens I heard a faint sound proceeding from another tuft six inches off, and at the same instant felt myself struck near the middle of the forehead; the blow was accompanied by a sensation as if a tiny drop of water had fallen there. On looking in  a glass I could see a little black sporange [sic] adhering where it struck, and it remained there for several hours. I immediately took the patch of P.kleinii from which it came (and I should mention that the stems of these specimens were bent almost at a right angle under the influence of the one-sided light beneath which they had grown) into an empty room, where I placed it with the upper portions of the bent stems pointing towards the window. I then laid a number of sheets of white paper around it, in the same horizontal plane; carefully closed the door and left it for an hour. This was just about midday. On returning I found all the sheets covered with a multitude of black dots, which a lens revealed to be the sporangia; each sporangium was surrounded by a brownish stain, produced by the liquid ejected at the same time. On measuring the distances to which the sporangia were thrown I found that a majority lay between three and four feet, but nearly a score lay at a greater distance than four feet, and the farthest that I could find at a distance of 4ft. 10in. When we consider that the utmost height of the individual fungi from which these bomb-shells proceeded did not exceed one tenth of an inch, and that therefore the last mentioned sporangium was thrown to a distance of nearly 600 times the height of the plant which threw it, we can form some idea of the enormous force exerted in this instance. It is as if a man of average height were able to throw his own head to a distance of nearly two thirds of a mile."

As I say, they don't write 'em like that anymore. I rest my case.

Something strange slithered here

This beautiful little packhorse bridge carries the footpath over Thorsgill beck beside Egglestone abbey in Teesdale. It probably dates from the 17th. century and countless feet must have passed over it since it was built. But when you stand on the top there is evidence of something else that slithered over its stones, around 300 million years ago.

One of the capstones carries this strange serpentine marking. Some long-extinct invertebrate left its trail when it wriggled across the tropical sea floor back in the Carboniferous, before the sediment turned to limestone.

Saturday, December 5, 2015

Durham Cathedral in Lego Bricks

If you happen in be in Durham city take a moment to have a look at this wonderful model of the cathedral built from Lego bricks, which is well on the way to completion.

Click here for more information

Thursday, December 3, 2015


Thursday's Guardian Country Diary is all about medlars, the fruit of Mespilus germanica. There is only one tree that I know of in Durham city and this year it produced a bumper crop.

For the first time ever we've been able to collect enough to make medlar jelly, a conserve that was popular in Victorian and Edwardian times and is said to go very well with cold meat. 

Medlar is an attractive small tree, with large white flowers in spring and bright autumn foliage that stays on the tree well into November. It's not native to the UK and comes from Asia Minor but it's certainly hardy enough to survive our winters up here in North East England. The trees are usually grafted onto quince, hawthorn or pear rootstocks.

The fruits resemble giant hawthorn berries and don't look very appetising. The French call them cul de chien, dog's arse; I'll leave you to decide why ........

Aside from their appearance, the other problem with medlars is that you can't eat them until they have softened - well, rotted really. The process is called bletting and our medlars are doing just that in our conservatory as I type.

Despite their appearance, I rather like the taste of these strange fruits. The texture of a well bletted medlar is like fudge and the flavour is like stewed apple with a hint of lemon. Traditionally they're eaten with port but they are said to go well with whiskey too - but then, so do most things. I'll be checking out this combination very soon.