Conidium

“ With a linear magnitude of 480, the sporangia have a transverse diameter of one to five millimeters, or a little more in the larger specimens. The filaments of mycelium, under the same magnitude, appear exceedingly thin and finer than a hair. The shape of the conidia, though presenting some varieties, is, notwithstanding, always perfectly characteristic. Sometimes they resemble in appearance the segments of a semicircle more or less great, sometimes the wings of butterflies, double or single. It is only exceptionally that their form is so irregular. ”

“ Yeast-like buddings from the conidia are produced in various Fungi, e.g. Ascoidea, Protomyces, Ustilagineæ, Ascomycetes, Tremellaceæ, etc. In the Ustilagineæ these conidia are an important element in the development. The budding conidia of Exobasidium forms a “mould” on the nutritive solution. The yeast-like conidia are not to be confounded with the “Mucor-yeast” (comp. Mucoraceæ) . For Saccharomyces see Appendix to the Fungi, page 176.
In a compound spore (i.e. when a mass of spores are associated together) each spore germinates on its own account. ”

“ The poisonous properties reside in an alkaloid, conine. The activity of the plant appears to depend upon the time of the year when it is gathered, being most powerful in May. The ready decomposition of the alkaloid by heat or age renders the extract of conium a very uncertain preparation, the conine being converted into an inert resinoid matter.
Conine the alkaloid is a colourless volatile oil, lighter than water, with an odour of mice. It is strongly alkaline, soluble in diluted acid, but its salts have not yet been crystallised. ”

“ The wind also very easily conveys the conidia to healthy Potato-fields and infects them. The enormous quantity of conidia and swarm-cells that may be formed in the course of a summer explains the rapid spreading of the disease; and the preceding makes it clear why wet summers are favourable to its existence. When the swarm-cells germinate, they round off, and then surround themselves with a cell-wall which grows out into the germ-tube, and pierces through the epidermis of the host-plant (Fig. 92) . Having entered the host, a new mycelium is formed. ”

“ When the conidia fall on the leaf, they remain there perfectly innocent and harmless unless they get a supply of water to enable them to germinate.... The disease makes its appearance in the end of July or the beginning of August, when we have, generally, very hot weather. The temperature of the atmosphere is very high, and we have heavy showers of rain."
The warmth and moisture are, in fact, the conditions necessary for the germination of the conidia. Their contents (zoospores) are liberated, and quickly grow in the leaf, and soon permeate every tissue of the plant. ”

“ The mycelium and conidia of this form were discovered in some Eocene silicified wood from Perekeschkul near Baku, on the shores of the Caspian. The conidia are elliptical or pyriform in shape and divided by a transverse septum into two cells. No traces were found of any special conidiophores. The mycelium consists of septate branched hyphae, rendered conspicuous by a brown colouration. Felix compares the fossil with the recent genera Cephalothecium and Cladosporium. ”

“ Whatever there may have been in the body before, certainly they produced a cadaveric ptomaine conine. For many animal tissues and fluids, especially if somewhat decomposed, yield not infrequently compounds of an oily nature with a mousey odour, fuming with hydrochloric acid and in short, acting just like conine. There is ample evidence, I have found, that conine or a substance possessing most, if not all, of its properties is at times actually produced in animal tissues by decomposition. ”

“ Other Coniine Bases.—Methyl- and ethyl-coniine have been prepared synthetically, and are both similar in action to coniine, but somewhat more like curarine. By the reduction of coniine with zinc dust conyrine (C8H11N) is formed; between coniine and conyrine stands coniceine (C8H15NO) . De Coninck has made synthetically by the addition of 6 atoms of hydrogen to β collidine, a new fluid alkaloid (C8H11N + 6H = C8H17N) , which he has called isocicutine: it has the same formula as coniine. Paraconiine Schiff prepared synthetically from ammonia and normal butyl aldehyde ”

“ The Extract of Conium, prepared by Mr. Barry, is the most powerful one I have ever used, indeed, until I tried it, I had no just idea of the virtues of Conium as a medicine; but I am now disposed to give credit to Stöerk’s account of its efficacy in various chronic diseases; and I have no doubt but that this valuable medicine has fallen into comparative disrepute and disuse from the bad quality of the extract commonly employed.” Dr. ”

“ A drachm and a half to two drachms, according to the degree of intensity desired, added to the ounce of the above collodion, which should have remained a few days to settle before sensitizing, I find to act most satisfactorily; in fine weather it is instantaneous, being, after a good shake, fit for immediate use. If the sensitive collodion soon assumes a reddish colour, it is improved by the addition of one or two drops of a saturated solution of cyanide of potassium ”

“ Cyanide of Potassium (Vol. ix., p. 230.) .—I have for a long time been in the habit of using a solution of the above-named substance for fixing collodion positives, because the reduced silver has a much whiter appearance when thus fixed, than when the hyposulphite of soda is used for the same purpose; but I cannot quite agree with Mr. Hockin that it is equally applicable to negatives, though in many cases it will do very well. I find the reduced metal is more pervious to light when fixed with the cyanide solution, particularly in weak negatives. ”

“ It is very rare that the protoplasm is not evacuated, and that the conidia give out terminal or lateral tubes in the manner that is normal to other species without papillæ. The germination just described does not take place unless the conidia are entirely surrounded by water; it is not sufficient that they repose upon its surface. ”

“ Microscopic Structure—Hemlock fruits differ from other fruits of the order by the absence of vittæ. [1149] In the endocarp, there is a peculiar layer of small nearly cubic cells surrounding the albumen. The cells of the endocarp are loaded with a brown liquid consisting chiefly of conine and essential oil.
Chemical Composition—The most important constituent of the fruits of hemlock Conine or Conia, C8H14NH, a limpid colourless oily fluid, 0·846 sp. gr. at 12°·5 C. It has a strong alkaline reaction, and boils at 170° C. in an atmosphere devoid of oxygen, without decomposition. ”

“ Even in nature one hydrogen atom of conine is frequently replaced by methyl, CH3; and commercial conine commonly contains, as shown by A. von Planta and Kekulé, methyl-conine, C8H14NCH3. Lastly there is present in hemlock fruits a third alkaloid having probably the composition C7H13N.
As to the yield of conine, it varies according to the development of the fruits, but it is at best only about 1⁄5 per cent. According to Schroff (1870) , the fruits are most active just before maturity, provided they are gathered from the biennial plant. ”

“ Where a large number of results are wanted quickly it is a very convenient method. The iodide process is very satisfactory when worked under the proper conditions.
CYANIDE METHOD.
The process is based upon the facts— (1) that when ammonia is added in excess to a solution containing cupric salts, ammoniacal copper compounds are formed which give to the solution a deep blue colour; and (2) that when potassic cyanide is added in sufficient quantity to such a solution the colour is removed, double cyanides of copper and potassium or ammonium being formed. ”

“ One hundred quarts of sap are said to yield from 1 to 2 pounds of coniferin-crystals. By now [Pg 197] allowing an aqueous coniferin-solution to run into a heated mixture of 10 parts potassium bichromate, 15 parts concentrated sulphuric acid, and 80 parts water, and heating for 3 hours in a flask with back-flow cooler, a liquid is obtained from which ether takes up a yellow oil. After treating the latter with animal charcoal, dissolving in ether and evaporating the latter, there remain colorless, acicular crystals of the odor and taste of vanilla. ”

“ The symbols [H+] , [CN−] and [HCN] denote the final concentrations for the condition of equilibrium, indicated in the equations on p. 180; in such a mixture [H+] is not equal to [CN−] , as it is in pure solutions of hydrocyanic acid in water. [CN−] , representing the total concentration of the cyanide-ion, is very much larger than [H+] , since the salt, potassium cyanide, produces the cyanide-ion in large concentrations. ”

“ The substance formed is very changeable, at least in the liquid where it is formed. It is decomposed by acids, alkalies, cyanide of potassium, and even decomposes spontaneously, the colour changing to yellow. It is precipitated by insoluble cyanides; hence when a dilute acid is added to the red solution, the dye is at once thrown down along with the cyanide of copper. If the precipitate thus obtained is treated with sulphuretted hydrogen, it is decomposed and the substance is set free. This substance can combine with iron, like cyanogen, so as to conceal the properties of the iron. ”

“ Penicillium crustaceum (P. glaucum, Figs. 111, 112) is an exceedingly common “Mould.” Its mycelium appears very frequently on any organic matter which is permitted to remain untouched, and soon covers it with a dense mass of blue-green [123] conidiophores. These branch at their summits and bear flask-shaped cells from which the conidia are abstricted. The ascocarps which, both in size and colour, resemble grains of sand, have only [124] been obtained in luxuriant cultivation with a limited supply of oxygen. ”

“ Its seeds indeed bear some resemblance to those of a Conium; and the flowers, which the able author just cited never saw, are uniform, scarcely radiant. The habit and foliage agree with Conium rather than with Tordylium. But, on the other hand, the character of the involucella dimidiata is not observable, and the crisped margin of the seeds answers better to Tordylium, though their strongly 3-ribbed disk is adverse, and rather belongs to Conium. To the latter genus I should perhaps consent to remove this species. Professor Sprengel, in his Prodr. Plant. ”

“ One part is soluble in 150 parts of water, [341] in 6 parts of ether, and in almost all proportions of amyl alcohol, chloroform, and benzene. It readily volatilises, and, provided air is excluded, may be distilled unchanged. It ignites easily, and burns with a smoky flame. It acts as a strong base, precipitating the oxides of metals and alkaline earths from their solutions, and it coagulates albumen. Coniine forms salts with hydrochloric acid (C8H15N.HCl) , phosphoric acid, iodic acid, and oxalic acid, which are in well-marked crystals. ”

“ Recalling the fact that the complex silver-ammonium-ion is not perfectly stable, one might suspect that the complex cyanide-ion, in turn, is not absolutely stable, and that the action, by which it is formed, is balanced, when equilibrium is reached, by a reverse action of decomposition. ”

“ On warming conine with sulphuric acid and potassium bichromate butyric acid is produced, and can be recognised by its peculiar odour.
3. If conine be added to a solution of alloxan a reddish-purple colour is produced in a few minutes, and white needle-shaped crystals form on standing. These crystals if dissolved in caustic potash solution produce a purple colour, and the odour of conine is given off.
Treatment.—Emetics, stomach pump, castor-oil, followed by ammonia and other diffusible stimulants. Artificial respiration should be resorted to and kept up for a long time. ”

“ The real cause of this rapid decomposability of the plasm, and of the accompanying formation of carbonic acid, is found in the cyanogen, a remarkable body composed of an atom of carbon and an atom of nitrogen, which, in conjunction with potassium, forms the well-known and very virulent poison, cyanide of potassium. The non-nitrogenous decomposition-products of the dead and the living albumin agree in the main, but their nitrogenous products are totally different. ”

“ The famous hemlock potion of the Greeks by which criminals were put to death [1145] was essentially composed of the juice of this plant. The old Roman name of Conium was Cicuta; it prevails in the mediæval Latin literature, but was applied, about 1541, by Gesner (and probably before him by others) to Cicuta virosa L., another umbelliferous plant which is altogether wanting in Greece and in Southern Europe generally, and does not contain any poisonous alkaloid. ”

“ Assay of commercial cyanide of potassium.—Break off 20 or 30 grams of the cyanide in clean fresh pieces, weigh accurately to the nearest centigram. Dissolve in water containing a little sodium hydroxide; transfer to a 2-litre flask: dilute to 2 litres; add a few grams of white lead; shake up and allow to settle. Run 50 c.c. of the clear liquor from a burette into an 8 oz. flask; add 2 or 3 c.c. of soda solution and 3 drops of potassium iodide. Titrate with the standard solution of silver nitrate. The percentage may be calculated by multiplying the number of c.c. ”

“ Jarvis, “is invisible under the most powerful microscope. The molecule is larger, but defies the microscope. But, having gone thus far, science had to go further. The next larger mass after the molecule, is the colloid. A colloid is a formless substance classified as a slime. It never takes a definite form like the crystalline substances. Solutions of gold can be made in the two forms—there is a colloidal gold and a crystalline gold.”
A look of stupefaction was on the faces of the inspector, the coroner and all that vast throng in the courtroom. ”