136 



HA RD WICKE' S SCIENCE- G OSSIP. 



(Senecio Jacobaa, L.) ; and there you see, still in bloom, 

 its hardy sister, which, however, is only an annual. 

 Why should one be perennial, the other annual ? 

 What is that downy matter peeping through the 

 green scales of the flower-head ? Are the scales 

 (involucre) the calyx, as we see in the primrose ? And 

 where are the petals ? Let us examine the flower for 

 ourselves. We find on inspection that the head is 

 made up of a large number of blossoms ; it must there- 

 fore be a composite plant. Hence the scales are not 

 the calyx ; but that feathery pappus is, and instead 

 of remaining behind when the seed is perfected, it 

 lends itself to the first gladsome breath, and dances 

 gaily away with its burden to seek a new home else- 

 where ! 



Having once begun to notice these things, we soon 

 find that the bare wall is anything but the bald, un- 

 interesting thing we took it to be. Here are the 

 remains of a curious plant (Galium mollugo, L.), 

 whose leaves are arranged in whorls around the stem, 

 and concerning which tradition has something to say. 

 It is popularly known as lady's bed-straw, and has 

 been included among the plants which served as a 

 bed for the Virgin during her stay at Bethlehem. 

 That neighbouring plant is called yarrow (Achillea 

 millefolium, L.), but ages ago the old Grecians regarded 

 it, or an allied plant, as sacred to Achilles (" Flora 

 Mythologica," p. 211), whence its scientific name, 

 Achillea. We can only mention, in passing, a few of 

 the other plants which are even now to be recognised 

 by the educated eye. Those rosettes of young leaves 

 will bud forth at an early period into plants of 

 whitlow grass (Draba verna, L. = Erophila), which 

 I never tire of studying ; and close by are similar 

 seedlings of hedge mustard (Sisymbrium thalianum, 

 Gaud.), and other cruciferous plants. Can we tell 

 why the leaves are thus spread out in a rosette ? It 

 is a pretty and instructive device, and if we can find 

 out nothing else we shall be repaid when we discover 

 this. The soft-leaved cranesbill (Geranium molle, L.), 

 parsley piert (Alchemilla arvensis, L.), autumnal 

 dandelion, plantain and hawk weed, are here also, 

 together with the cocksfoot and other grasses, which 

 in themselves would find us work for many a long 

 hour. 



But these higher forms of plant-life are as nothing 

 compared with the host of cryptogams which are 

 clamouring for our notice. To begin with the lichens, 

 we find here that curious form (Lecidea geographica), 

 L. Brackel, which has come to be known as the 

 map lichen on account of the peculiar markings of the 

 thallus. Just now heaps of dog's liverwort (Peltigera 

 canina, L.) are in splendid fruit about midway along 

 the wall, in a place where the earth has become 

 specially productive; nor must we neglect the 

 common "cup moss," as our country friends usually 

 term another of the lichens (Cladonia pyxidata, Fr.). 

 What, however, is this brilliant display which I have 

 just stumbled across ? It must be some kind of moss, 



you say. Yes. It is one of the mosses, but we 

 have just come upon it at the right moment to 

 observe its delicate and elaborate organs of repro- 

 duction in their glory. It is only a common moss 

 (Polytrichum commune, L.), but we shall find it a 

 delightful object for the microscope, and we will refer 

 to a little work on Plant-Life (by E. Step) for some 

 account of it, if we cannot command a more elaborate 

 work. The twisted moss (Tortula), or screw moss as 

 it is often called, the cushion moss (Grimmia), and 

 another species (Hypnum cuprcssiforme, L.), are all to 

 be found here ; and while their " fruit " is always an 

 interesting study, their cells are no less so ; and we 

 may read what Mr. Lett has to say about them in the 

 January issue of the "Journal of Microscopy." 



We have not by any means exhausted the list, even 

 of vegetable productions, which I found on this bit of 

 wall one day in December. The Fungi were repre- 

 sented by an agaric, or gilled toadstool, a peziza, with 

 its spores contained in asci or sacs, a parasitic rust 

 which was able to live in the tissues of its host plant 

 very snugly, when many other forms were destroyed 

 by the cold ; and other genera. Then there were 

 certain minute Algce and microscopic forms of life 

 which well deserved attention, but could not be 

 studied on the spot, and are therefore left unnamed. 



Hunting thus among the plants, we shall find, even 

 in mid-winter, a considerable number of representa- 

 tives of the animal kingdom. In the crevices of the 

 wall I gathered a snail (Helix), a spider, and a 

 Trombidium ; and other creatures were snugly 

 reposing at the foot of the dyke, whose peaceful 

 slumbers I dare not disturb. We will now leave our 

 wall for a time ; and in May, if the weather is fair and 

 the season well advanced, we will take a run out, and 

 see what the .effect of the winter's snow and the 

 spring's genial breath has been upon our friends. 



Carlisle. 



JOTTINGS CONCERNING CERTAIN FRUIT 

 TREES. 



By Mary B. Morris. 



No. VII.— The Walnut Tree. 



THE common walnut tree, known to botanists as 

 Juglans regia, is found growing wild so ex- 

 tensively as to render it difficult to be quite certain 

 of the exact region which can be called its native 

 habitat. In all probability it is a native of the 

 province of Ghitan in Persia, on the shores of the 

 Caspian Sea. It would appear also to be indigenous 

 in Northern China and Japan, in the Northern 

 Himalayas, and in Burmah. Asiatic, we may say, 

 in its origin, it has been a cultivated tree from very 

 early times throughout Asia and Europe. De Can- 

 dolle states that many species of Juglans existed in 

 the tertiary and upper tertiary epochs, leaves of such 

 having been found in the tufas of the upper tertiary 



