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Chitin

February 26, 2010

Thoreau

November 15, 2006

To study lichens is to get a taste of earth and health, to go gnawing the rails and rocks.

A taste for this study is an evidence of titanic health, a sane earthiness.

It fits a man to deal with the barrenest and rockiest experience.

– so the lichenist loves the tripe of the rock, – that which eats and digests the rocks.

I feel like studying them again as a relisher or tonic, to make life go down and digest well

a sort of winter greens which we gather and assimilate with our eyes

lines drawn from the Journals of H.D. Thoreau, February 7, 1859

Stridulation

July 5, 2006

“Even insects express anger, terror, jealousy, and love by their stridulation.”

-Charles Darwin, The Expression of the Emotions in Man and Animals, 1872

Stridulation is the production of sound by an insect, caused by the rubbing together of body parts. The bioacoustic (or zoosemiotic) ambience of summertime in Minnesota is replete with cricket, grasshopper, and katydid calls, all of which insects stridulate. Crickets and katydids produce their calls by rubbing together their wings. They have a pair of structures, file and scraper, on each forewing – the sawing of the rigid scraper across the comb-like file produces vibrations which become sound.

Crickets. In Minnesota, the most cosmopolitan cricket is the field cricket, the common name for several cricket species belonging to the genus Gryllus. A multitude of other cricket species, including the house, ground, camel, tree, and prairie crickets, reside in Minnesota as well.

The relationship between air temperature and the rate at which crickets chirp is expressed by Dolbear’s Law as follows, where T is the temperature (in Farenheit) and N is the number of chirps per minute:

T_F = 50 + left ( frac{N-40}{4} right )

Amos Dolbear published this formula in his 1897 article entitled, “The Cricket as a Thermometer.” Dolbear is more well known for his less whimsical 1865 invention of a telephone receiver 11 years before the similar machine for which Alexander Graham Bell, not Dolbear, was recipient of a patent.

Alternately, it is said that by counting the number of chirps produced by a field cricket during a 15-second period and adding 40 to that number, a rough approximation of the temperature can be derived.

Katydid is a name onomatopoeic for that insect’s call, at least for “true katydids” (Pterophylla camellifolia), whose call it is said, sounds like “katy did, katy didn’t” (audioclip). True katydids have only recently pushed the north-most boundary of their territory into Minnesota, where they have been found in the Twin Cities metropolitan area. Formerly, true katydids were known only in the southern and eastern United States. This is probably accounted for by the overall rise in temperature in Minnesota – since 1981 Minnesota has seen 8 of its 20 warmest years on record. The other katydids, the ones seemingly long-resident in Minnesota, include bush, meadow, cone-headed, and shield-bearing type katydids.

Grasshoppers, unlike crickets and katydids, stridulate with their legs and wings or abdomen; a small row of toothy structures on the inside of their hind legs is drawn across a ridge on their wings or abdomen to produce calls similar to those of crickets and katydids. Grasshoppers also crepitate, by snapping together their wings during flight. In Minnesota there are about 60 different kinds of grasshoppers. In the mid-1870s, floods of grasshoppers called Rocky Mountain Locusts (locusts are grasshoppers in “swarming” phase) scoured the Great Plains, devouring crops, stripping trees, and caking railways to such an extent that they became inoperable. The visitations of the “Rocky Mountain Locust” are recalled in Laura Ingalls Wilder’s On the Banks of Plum Creek:

The Cloud was hailing grasshoppers. The cloud was grasshoppers. [ ] Their thin, large wings gleamed and glittered. The rasping whirring of their wings filled the whole air and they hit the ground and the house with the noise of a hailstorm.

It is said that the sound of their chewing was also deafening. It is also said that where crops and greenery were already obliterated, the clothes were eaten from clotheslines, the wood of axe handles and leather of saddles were gnawed on, and supposedly the wool was consumed from the very backs of sheep. The United States government in 1876 declared the grasshoppers “the single greatest impediment to the settlement of the country.”

Estimates suggest that the locusts from a swarm that descended on Nebraska in July of 1874 covered 198,000 square miles, and numbered approximately 12.5 trillion insects, amounting in sheer biomass to as much as 27.5 million tons. The locusts came five consecutive years – from 1873 to 1878. At that time, 69% of agricultural lands in Minnesota were consigned to the production of wheat. In an effort to arrest the devastation being wrought on the local wheat crop, the state put a bounty on locusts and their brood, which varied in award from 50 cents a bushel for locusts to $5 dollars per bushel for locust eggs (a bushel is just over 35 liters).

Minnesota Governor John Pillsbury (Pillsbury of milling fame) declared a state-wide “day of prayer” on April 26th, 1877, to ask mercy from the depredations of the locusts. Grasshopper Assumption Chapel in Cold Spring, MN is a memorial to the fabled insecticidal storm of freezing rain that supposedly came and “smote” the locusts following the so-called “day of prayer.”

*

Shortly after the 2003 North American Blackout an article appeared in The New Yorker (A Rare and Different Tune) in response to the theretofore collectively overlooked insect singing with which New Yorkers were greeted during the Blackout.

Some people go through life never knowing what a katydid is, or what kind of bug makes which sound, when, and for what reason. But the particular bug sounds chronicled below took place under a big linden, just outside the city. This was during the blackout, a few weeks ago, when anyone who was near trees might suddenly have noticed, in the absence of some of the other usual night noises—air-conditioners, floor waxers, Ernie Anastos—that the bugs, whatever they were, were making a hell of a racket.

A discussion, not quite an argument, arose over what was making which sounds. The more you listened to the trees, the stupider you felt.

Thank God the electricity came back on, because it gave everyone a chance to log on to the Internet for some insta-entomology.

*

What distinguishes stridulation from the production of the more bracing strains for which cicadas are known are the actual sound-producing organs cicadas possess. Cicadas do not stridulate, instead male cicadas have abdominal structures called tymbals, which are fine exoskeletal membranes that vibrate rapidly. Cavities within the cicada’s body augment this sound like resonance chambers. I read somewhere that philologists once thought the Spanish word for cigar (cigarra) derived from the word cicada, claiming that the resemblance between the two words owed to the resemblance of the cigars first seen by Spanish conquistadores to cidadas – these cigars were the kind tapered at both ends, now called perfecto.

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The cicadas commonly known as “seventeen-year locusts” are periodical cicadas well-known in the eastern United States for exilic, 17-year periods of collective dormancy followed by the sudden, exuberant emergence of incalculable multitudes. The cyclical emergence of these cicadas are to entomology what the return of certain comets are to astronomy. 2004 was the year of the emergence of “Brood X” in anticipation of which an article on the subject appeared in The New York Times, May 20th of 2004, entitled, The Orgy in Your Backyard:

They overwhelm the cornerstone of rationality: our ability to quantify nature. In fact, if we do want to try to quantify cicadas, we have to deal with some incomprehensibly big numbers. When the periodical cicadas are in their full glory, there will be an average of about 100,000 insects per acre spread across an area four times the size of Pennsylvania. That works out to about 10 trillion cicadas, 1,500 for each human on earth.

The cicadas will outweigh the population of the
United States (even with our obesity problems) by a factor of nearly two.

A few weeks after their arrival, the cicadas will die, leaving piles of depleted corpses and more than 500 trillion eggs. In a single square mile of forest with the densest populations, there will be as many eggs as there are stars in the Milky Way.

A cicada shell;
it sang itself
utterly away.

-Matsuo Bashō

For diagnostic reference of insect sounds, I recommend the website Singing Insects of North America.

Butterworts

May 25, 2006

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Butterworts, L. Pinguicula, are one of 13 species of insectivorous plants that grow in Minnesota, the others being sundews (4 species), bladderworts (7), and pitcherplants (1). Butterworts, and nearly all plants that supplement their nutriment by consuming insects, reside in damp environments with low nitrogen levels, such as swamps or wet rock surfaces. In Minnesota, butterworts inhabit very specific microclimates in northern Minnesota. One such place is along Lake Superior (see Butterwort Cliffs Scientific and Natural Area). The photograph above is a butterwort sheltered within a niche in the exposed bedrock of the Superior shoreline near Gooseberry falls. Exoskeletal husks of consumed insects blot its leaves like tiny ink spots.

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The dietary proclivities of butterworts were first documented in Charles Darwin’s Insectivorous plants (New York, D. Appleton & Co., 1875), in which he writes: “I was led to investigate the habits of this plant by being told by Mr. W. Marshall that on the mountains of Cumberland many insects adhere to the leaves.” Butterwort leaves glisten with adhesive and digestive fluids, the smell of which insects apparently find, to their demise, alluring. Once an insect has alighted upon the leaves of the butterwort and cannot prise itself from their surface, the throes of the struggle that ensues incite the plant to secrete additional adhesives, as the edges of the foliage curl up around the insect.

The first written description of butterworts was published in Austrian naturalist Vitus Auslasser’s treatise on medicinal herbs, Macer de Herbarium, in 1479. Auslasser notes the mucilagenous surface of the leaves, calling the plant a “lard herb” (zitroch kraut). The Latin genus name Pinguicula comes later, from the Swiss naturalist Conrad Gesner. In his 1561 work Horti Germaniae, Gesner, like Auslasser, describes the leaves as “fat” – “pinguia et tenera folia” (“fat and tender foliage” – pinguia from the Latin pinguis, meaning fat). The “fat” of these appellations persists in the English common name “butterwort.”

Wort (or wurt or wyrt) is an Old English word meaning plant, or herb, and has similarly antiquated cognates in other European languages (wurz in Old High German, for example). Wort persists in modern English usage as the second element in compound words used as common names for some plants, like Spleenwort, Lungwort, Bruisewort, etc. Such plant names are associated with the Doctrine of Signatures, a Christian metaphysical hermeneutic in which resemblance figures as the basis of interpretation. For example, the Spleenwort I referred to above is a fern (Asplenium) which bears spores on the undersides of its leaves in a pattern that was thought to resemble the spleen – thus the fern came to be used for treating medical conditions associated with the spleen. The doctrine insinuates affinity between (seemingly) categorically distinct things. The uses to which such plants might be put are not limited to the medicinal – resemblance in the Doctrine of Signatures serves as index to all the host of Creation in which God inscribed His mark. The name Mugwort (Artemisia vulgaris), for example, is thought to be derived from the habit of using the herb in the brewing of beer. Although the name “butterwort” does not suggest its use as medicinal herb, it is nevertheless named for that to which it bears a resemblance (fat), and perhaps a use to which it was once put as well.

Linnaeus wrote about butterworts in Flora Lapponica – his survey of the flora of Lappland, and in his journal of 1732, written during his time traveling above the arctic circle and living among Sápmelaš (or “Sami”) tribes when he was in his mid-twenties. These narratives are decidedly “ethnobotanical” in nature – the term was coined much later in 1895, by John William Harshberger. In Linnaeus’ illustration below, Pinguicula is marked 2. and 3. The other two images are from the cover of Flora Lapponica. In one, a depiction of the bucolic backdrop to the ambitious notetaking of Linnaeus’ youth – natives floral, faunal, and human.

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Among his notes, Linnaeus describes how butterwort leaves were used by Sami to make a yogurt-like fermented milk called filmjölk. Butterwort leaves had for centuries been in use in northern Europe and parts of the Alps for the purpose of making various types of fermented milk. Most of the Norwegian names for butterworts reflect this use of the leaves as a curdling agent: tettebugge (thickening old man), tettegress (thickening grass), vuodjalasta (butter leaf), istegras (curdle grass), melkekrossen (milk cross), etc. Likewise, the word “yogurt” (yoğurt) refers to thickness – it is derived from Turkish words, yoğun (“dense”) and/or yoğurmak (“to make dense”), in reference to the methods which produce it.

Filmjölk contains unique strains of bacteria unlike those found in commercial yogurt, which is cultured with Lactobacillus and Streptococcus thermophilus species. Filmjölk requires the species Lactococcus and Leuconostoc. Fil (Filmjölk), is the popular name for what is now a product sold commercially in 1-litre packages in Sweden.

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In Norway, Tjukkmjolk, is likewise commerically available. It is actually the first food product from Norway with a “controlled origin” label. It is made from cultures obtained from Pinguicula vulgaris.

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Slime molds

May 4, 2006

Slime molds, also called myxomycetes (Gk: myxo = mucus, mycetes = fungus) are organisms that are neither plants, nor animals, nor fungi, nor truly “mold,” which is fungus. They are protists.

Protists are members of the kingdom Protista, which includes protozoans and algae, in addition to slime molds. Protozoa, algae, and slime molds were formerly classified according to their respective morphological affinities with members of the kingdoms Plantae, Animalia, and Fungi. Thus, for about 150 years, protozoans were categorized as animals (protozoa in Greek means “first animal”), algae as plants, and slime molds as fungus. Familiar examples of protists include organisms such as amoeba and paramecia, and examples of algae might include species of the porphyra genus of red algae – a group of seaweeds best known as nori.

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concrete

April 4, 2006

The approximate date and location for the earliest known use of lime mortar, which is made of sand and quicklime, is 4,000 bce, Egypt. Quicklime is a powdery and friable substance made from limestone (containing calcite) that has been burned at a temperature of approximately 900 degrees (achieved with the use of a kiln [1]). At this temperature calcite releases carbon dioxide, leaving behind calcium oxide, or quicklime, in a process called calcination.

Limestone is sedimentary rock, the bulk of which is calcite, which in turn is made up of fossilized marine organisms and their shells. Calcite is among the most ubiquitously deposited minerals on the surface of the earth, representing in weight about 4% of the earth’s crust.

Various mortars and cementitious materials, not all of which contained lime, were utilized in the construction of the imperial infrastructres of Assyria, Babylon, Greece, and the Roman, Chinese, Mayan, and Mexica/Nahua Empires. In the West, cement fell out of use with the fall of Rome. Political seisms animate the history of this technology; the wax and wane of its use as a stuff of Empire.

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whisky

March 31, 2006

The malted barley grain from which whisky is made is first soaked in water until it germinates, and is then dried over peat fires. The peat in question is a material formed by the accumulation of decaying plant biomass, specifically that of sphagnum moss.

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