Page:The New International Encyclopædia 1st ed. v. 05.djvu/345

* CONIFERS. 293 CONIINE. exposed ovules, and the seed either ripens fleshy or lias a Heshy investment. It includes two tribes — the I'odocarpeiv, genera of the Southern Hemisphere (the genus Podocarpus, with forty species, being the second largest of tlic conifers), and the Taxese, including the yews (Tuxus) and their allies. Some of the conifers, as the pines and juni- ])ers, are very widely distributed, while others, like the gigantic redwoods {Sequoia) of Califor- nia and the bald cypress (Taxodiinn) are now very much, restricted. The greatest displays of much restricted ('endemic') genera occur in the China-Japan region, and in the Australasian region. Fossil Forms. Fossil remains of Conifera>, consisting of branches, leaves, cones, and seeds, are found in great abundance in the most recent of the Mesozoic and in the Tertiary formations, and have been referred to genera still living on account of their resemblance to them. But only when such determination is based on well-pre- served cones may it, as a rule, be considered sat- isfactory. Leaves and leaf-bearing branches fur- nish only in exceptional cases a basis for the determination of the genera, as there are recent genera from dilTerent families in which the leaf- ing branches cannot be distinguished at all by their outward appearances. It is no better with the fossil woods, for it is known that fragments of wood having the struc- ture of living conifers are found in ever}- state of preservation throughout the entire series of geologic formations from the ^Middle Devonian upward. The great hopes entertained that they would furnish important results have, according to Solms-Lanbach, not materialized, owing to the uniformity of structure which characterizes sec- ondary growth in thickness in Conifer;p. More- over, the Cordaites, which stand between the Cycadacea" and Coniferoe. have a woody struc- ture distinguishable only in entire sections of the stem. Goppert's example in dealing with the fossil woods has been followed, and they are di- vided into general groups according to their re- semblances to the wood of modern genera, as: Araucaroxylon (Dadoxylon), like wood of Nor- folk Pine — Araucaria: Pissodendron : Cupress- oxylon, like wood of cypress; Pityo.x^don, like wood of pine: Cedroxylon. like wood of cedar; Taxoxylon, like wood of yew. Of these, Taxoxy- lon is known only from the Tertiary ; Cupress- (ixylon occurs only from the Chalk onward; pine and cedar woods only from the Tertiary on- ward. Araucaroxylon and Pissodendron are the only types of coniferous wood found in the Paleozoic formations. To Araucaroxylon prob- ably belongs the wood of the Carboniferous pines and Dawson's species of Dadoxylon and Ormoxy- lon, from the Canadian Middle Devonian. But the wood of Cordaites has also the Araucaroxy- lon structure. The presence of true Conifera; with this wood structure is, however, known from the Carboniferous. The stems of Protaxites Logani and Xematoxylon erassum, from the Lower Devonian of Canada and New Brunswick, which were described by Dawson as the oldest Conifer remains, are now considered to be remains of alga;. It has been determined that the conifers origi- nated in the Arctic region, from whence they have spread over the globe. The pines (Pinus) appeared first in the European early Cretaceous beds, where their cones are found, and they be- came very abundant, in the Tertiary. The tirs are known from the .Jurassic of Spitzbcrgen and Siberia, and the cedars date also from the .Iiiras- sic. The .raucarians, to which belong also the •TaxodiiC (liald Cypress) and the Sequoiie (Red- wood), are tliouglit to be represented by the gigantic Walchia of Permian age. The ty|)ical -Uncrican bald cypress (Taxodium distichum), hich abounds in the swamps of Florida, occurs as the same species in the Miocene of Middle Europe. The Voltzias, so common in the Trias- sic sandstones of Germany, may also belong to the Taxodiip. The cypress appears in the Triassic with a form extremely similar to a genus now found only in Africa — Widdringtonia. The cedar of Lebanon, the junipers, and others, make their earliest appearance in the Cretaceous of Green- land, and are found in later formations — Upper Cretaceous and Tertiary — of Jliddle Europe, an indication of the migration they made with the passing of geologic time. Salisburias are to-day represented by a single living type, the famous ginkgo (q.v.), which was first known in the cultivated state in the groves of Chinese tem- ples. Ginkgo is the last descendant of a once great race, with ancestors that reach back as far as the Lower Carboniferous, and nourished, dur- ing those periods, from the Triassic onward, in the northern parts of Europe, as Spitzbergen and Siberia, etc. BiBLiOGRAniY. Dawson, "The Fossil Plants of the Devonian and Upper Silurian Formations of Canada," Canadinn Groloiiical (S'Hrrcy (Otta- wa, 1881, 1882) ; Gijppcrt, "Jtonograiihie der fossilen Coniferen," Xaturkinidige VerhandUnge ran de Hollandsche Maatschai>pij der Weten- schappen, te Haarlem, ser. 2, vol. vi. (Leyden, 1850) ; Zittel and Schimper, Handbuch der PaliJontoJofiie. part ii. (Leipzig, 1879-8.5) ; same, French edition (Paris. Munich, and Leipzig, 1887) : H. Graf zu Solms-Laubach, Fossil Bot- aufi (Oxford, 1801). For illustrations, see AR.rc.RiA ; Pines, etc. CONIINE (from Lat. conium, Gk. Ki>v£iov, hdncion. hemlock). C5H.7N. The active alka- loid principle of hemlock, the seeds of the spotted hemlock plant (Conium maculatum, Lin- ne). Being a volatile substance, coniine may be readily obtained from the seeds by distilling with water which contains a little soda in solution; coniine then passes over with the water in the form of a yellowish oil, but, when purified by re- distillation, it is obtained as a colorless, trans- parent, oily liquid having a penetrating hemlock- like odor, commuiiicatiiig a liurning .sensation if ap]died to the tongue, and acting as a very ener- getic poison. It has a poAverful alkaline reaction and precipitates metallic oxides from many salts. Strong sul])huric acid causes its compounds to assume tirst a purple-red and then an olive- green color, while nitric acid gives a blood-red color that fades into an orange. It is mod- erately soluble in water, its solutions having the propertv of turning the plane of pohnrized light to the' right. If pure, it boils at 107° C. The chief physiological effect of coniine is .a powerful depression of all motor nerves, begin- ning at their periphery and gradually ascending to the spinal cord. As a result, all motion, voluntary and reflex, is paralyzed, although the muscles are not afl'ected. This leads to enfeeble-