Leucothea

“ The simple leaves, which are of small size and do not possess a ligule, are arranged spirally around the branched stem in the majority of the species. The roots of the erect forms often grow downwards in the cortex of the stem to reach the soil. The anatomy of Lycopodium presents considerable variety in detail, but the stem is always monostelic and the development of the xylem centripetal, the protoxylems being situated at the periphery of the stele; pericycle and endodermis surround the stele, and the wide cortex may be more or less sclerenchymatous. ”

“ Lepidodendra, twigs of Bothrodendron [169] species of conifers, fern rhizomes, and Aphlebiae [170] have masqueraded as herbaceous lycopods. It is obvious that an attempt to identify fossils presenting a general agreement in habit and leaf-form with recent species of lycopods must be attended with considerable risk of error. Recent Conifers include several species the smaller branches of which simulate the leafy shoots of certain species of Lycopodium and Selaginella, and it is not surprising to find that this similarity has been responsible for many false determinations. ”

“ Lycopodium. It would be out of place in a volume devoted mainly to fossil plants to attempt a comprehensive account of the general morphology of recent species, and indeed our knowledge of the anatomical characters of the genus is still somewhat meagre. For purposes of comparison with extinct types, it is essential that some of the more important morphological features of existing species should be briefly considered. The additions made to our knowledge of the gameophyte [92] of European and tropical species during the last two decades have revealed a striking diversity in habit. ”

“ Lycopodium, represented by nearly 100 species, forms a constituent of most floras: epiphytic species predominate in tropical regions, while others flourish on the mountains and moorlands of Britain and in other extra-tropical countries. For the most part Lycopodium exhibits a preference for a moist climate and appears to be well adapted to habitats where the amount of sunlight is relatively small and the conditions of life unfavourable for dense vegetation. Mountains and islands constantly recur as situations from which species have been recorded. ”

“ In several species, grouped round the widely distributed type Lycopodium Selago Linn., the comparatively short, erect or suberect, shoots form fairly compact tufts; the ordinary foliage-leaves function as sporophylls, and the sporangia are not localised on special portions of shoots. From this type, we pass to others in which the fertile leaves tend to be confined to the tips of branches, but hardly differ in form from the sterile. ”

“ The expansion of the wings is 11⁄2 inches. The fore-wings are dull ochreous, with the veins obscurely indicated by black and white dots; there is a curved series of minute black dots near the termen. The hind-wings are pale ochreous, clouded with grey towards the termen. The cilia of all the wings are dull ochreous. This insect may be distinguished from Leucania unica by its larger size, duller coloration, less oblique termen of fore-wings, and simple antennæ in the male. ”

“ The danger which should be borne in mind, in adopting as a matter of convenience the term herbaceous as a sectional heading, is that it should not be taken to imply a complete inability of the so-called herbaceous types to make secondary additions to their conducting tissues. The specimens on which the species of Lycopodites and Selaginellites, (genera which may be designated herbaceous,) are founded are preserved as impressions and not as petrifications; we can, therefore, base definitions only on habit and on such features as are shown by fertile leaves and sporangia. ”

“ A description by Mr Rodway [237] of Lycopods on the border of a savannah in Guiana forming a miniature forest of Pine-like Lycopodiums might, with the omission of the qualifying adjective, be applied with equal force to a grove of Lepidodendra. The equal dichotomy of many of the branches gave to the tree a habit in striking contrast to that of our modern forest trees, but, on the other hand, in close agreement with that of such recent species of Lycopodium as L. cernuum (fig. 123) , L. obscurum (fig. 124) and other types. ”

“ Where the Leucospis flies, she does not budge. So great is her assurance that she comes right into my study, to my work table, and disputes my ownership of the nests whose occupants I am examining. She operates under my lens, she operates just beside my forceps. What risk does she run? What can one do to a thing so very small? She is so certain of her safety that I can take the Mason's nest in my hand, move it, put it down and take it up again without the insect's raising any objection: it continues its work even when my magnifying glass is placed over it. ”

“ As far as number is concerned, the living Club Mosses represent a comparatively insignificant group when compared with the Ferns. In all the world there are probably not more than five or six hundred species. These are very widely distributed, and there is hardly any part which cannot offer at least a few species. We have five species of Lycopodium in the United Kingdom. All are rather local, though often enough they occur in great abundance in special localities. ”

“ At first I took it for some species of Andromeda, but on bringing it to book found it to be Leucothoë. I was delighted to see it. It is a satisfaction to have a familiar name begin to mean something. Finally, a year or two later, passing in winter through a bit of [165] swamp where I had been accustomed to wander as a child, with no thought of finding anything new (as if there were not something new everywhere) , I stopped before a bush bearing purple buds and clusters of dry capsules. ”

“ Every dog knows his own trick.
Next comes a dry, homely, crooked, blackish, dead-looking twig, the slender divisions of which are tipped with short clusters of very fine purplish buds, rich in color, but so small as readily to escape notice. This I broke from a bush in a swampy place. It is Leucothoë, a plant of special interest to me for personal reasons. Year after year, as I turned the leaves of Gray’s Manual on one errand and another, I read this romantic-sounding Greek name, and wondered what kind of plant it stood for. ”

“ In Leuchtenbergia, the tubercles fall away as the plant increases in height, leaving a bare, woody stem similar to that of a Yucca.
Cultivation.—The Leuchtenbergia has always been difficult to keep in health. It thrives best when kept in a warm, sunny house during winter, and in an exposed, airy, warm position under a frame during summer. It may be watered regularly whilst growing—that is, from April to September—and kept quite dry all winter. The soil should be well-drained loam, and the roots should have plenty of room. A specimen may be seen in the Kew collection. ”

“ The sexual organs are represented by antheridia and archegonia; 32the male cells are provided with two cilia except in Isoetes which has multiciliate antherozoids like those of the ferns.
The existing Lycopods, though widely distributed, never grow in sufficiently dense masses to the exclusion of other plants to form a conspicuous feature in the vegetation of a country. The inconspicuous rôle which they play among the plant-associations of the present era affords a striking contrast to the abundance of the arborescent species in the Palaeozoic forests of the northern hemisphere. ”

“ But whatever their functions may be, great assistance may certainly be derived from their various modifications, in distinguishing genera. Their importance however in this respect, like that of all other parts, not only in this, but, as I apprehend, in every natural family, is very unequal, and in some cases seems to be entirely lost. Thus, in the genus Leucadendron as it is here constituted, they are wanting in several species, and in some I am inclined to think exist only in the males. ”

“ In its lowest fossiliferous beds we detect a Lycopodite which not a little resembles one of the commonest of our club mosses,—Lycopodium clavatum,—with a minute fern and a large striated plant resembling a calamite, and evidently allied to an existing genus of Acrogens, the equisetaceæ. In the Middle Old Red Sandstone there also occurs a small fern, with [Pg 42] some trace of a larger; and one of its best preserved vegetable organisms is a lepidodendron,—an extinct ally of the Lycopodiums ”

“ The Lycosa’s affection for her offspring hardly surpasses that of the plant, which is unacquainted with any tender feeling and nevertheless bestows the nicest and most delicate care upon its seeds. The animal, in many cases, knows no other sense of motherhood. What cares the Lycosa for her brood! She accepts another’s as readily as her own; she is satisfied so long as her back is burdened with a swarming crowd, whether it issue from her ovaries or elsewhence. ”

“ The form of the leaf-scars varies according to the age of the branch and their disposition is far from constant even on the same specimen; in some cases the scars are in fairly regular whorls (fig. 212, G; an Irish specimen) while in others they are in regular spirals. This irregularity of arrangement, which is well illustrated by Nathorst’s figures of Bear Island and Irish specimens, finds its counterpart, though in a less marked form, in recent species of Lycopodium, e.g. L. Selago. ”

“ Lycopodium rufescens Hook. An Andian species with stout dichotomously branched erect stems bears on the younger shoots crowded leaves with their thick and broadly triangular laminae pointing upwards, but on the older and thick shoots the laminae are strongly reflexed (fig. 121, A) . The lower part of the specimen represented in fig. 121, A, shows tangentially elongated scars and persistent leaf-bases or cushions left on the stem after the removal of the free portions of the leathery leaves, a surface-feature which also characterises the Palaeozoic genus Lepidodendron. ”

“ Helotarsus ecaudatus of the whole Ethiopian Region is black, with maroon back and tail, and a broad grey band across the secondaries; {154}the wide crest, short rectrices, red cere, lores and feet, rendering it most remarkable. H. leuconotus is hardly more than a creamy-backed variety. It sails aloft in powerful style, and dashes like lightning upon the snakes, mammals, and lizards, which form its prey; the nest of sticks is placed in trees or rocks, and contains, it is said, from two to four white eggs. ”

“ Isoetes (fig. 132) , of which Mr Baker in his Handbook of the Fern-Allies enumerates 49 species, is a type apart, differing in habit as in certain other characters from the other members of the Lycopodiales. Some botanists [89] prefer to include the genus among the Filicales, but the balance of evidence, including resemblances between Isoetes and extinct Lycopodiaceous plants, would seem to favour its retention as an aberrant genus of the group Lycopodiales. Some species are permanently submerged, others occur in situations intermittently covered with water, and a few grow in damp soil. ”

“ A second genus, which I shall hereafter publish with the name of Leucolæna, is worthy of notice on account of the great apparent differences of inflorescence existing among its species; which agree in habit, in the more essential parts of fructification, and even in their remarkable involucella. Of this genus, one species has a compound umbel of four many flowered radii; a second has an umbel of three rays with two or three flowers in each ”

“ It was in the first week of July that I saw the inoculation begin on my Chalicodoma sicula nests. The parasite is at her task in the hottest part of the day, close on three o'clock in the afternoon; and work goes on almost to the end of the month, decreasing gradually in activity. I count as many as twelve Leucopses at a time on the most thickly-populated pair of tiles. The insect slowly and awkwardly explores the nests. It feels the surface with its antennae, which are bent at a right angle after the first joint. ”

“ Daily, if the sky be clear, the Lycosa, carrying her young, comes up from the burrow, leans on the kerb and spends long hours basking in the sun. Here, on their mother's back, the youngsters stretch their limbs delightedly, saturate themselves with heat, take in reserves of motor-power, absorb energy. ”

“ We here saw trees allowed to stand in gardens, and some of the Batoka even plant them, a practice seen nowhere else among natives. A species of leucodendron abounds. When we meet with it on a spot on which no rain has yet fallen, we see that the young ones twist their leaves round during the heat of the day, so that the edge only is exposed to the rays of the sun ”

“ Where leeches occur they need no coaxing to bite, but fly at the white skin like furies, and refuse to let go: with the fingers benumbed, though the water is only 60°, one may twist them round the finger and tug, but they slip through. ”

“ As remarked in the first part of this work, Leuckart long ago pointed to the Salmonidæ as probably furnishing the intermediate host of this worm; and he disproved the views of Knoch, of Petersburg, who thought he had reared Bothriocephalus latus in the dog in a direct manner. I have already called attention to the opinion of Dr Fock, of Utrecht, who thinks the human bearer may become infested by the consumption of the little fresh-water bleak (Leuciscus alburnus) . ”