126 



HARDWICKE'S SCIENCE-GOSSIP. 



the vegetable kingdom they must be referred, 

 although possessing a more highly developed struc- 

 ture than the modern horsetails. The Equiseta are 

 strange plants, having at the present day but one 

 single genus with no definite links allying it to other 

 Cryptogamic orders. In the Carboniferous period they 

 mui.t have proved an important item in the vegeta- 

 tion, and many of them grew to a vast size, and 

 probably formed dense forests over the low-lying 

 marshy flats of the period. The few living species of 

 Equiseta are, for the most part, small insignificant 

 weeds, although some one or two of the American 

 species attain a height of several feet. 



The recent plants ' ' have slender, hollow, and 

 jointed stems, each joint terminating exteriorly in a 

 toothed membranous sheath composed of leaves re- 

 duced to this elementary state ; whorls of branches or 

 brauchlets are given off at the joints in some species, 

 with small leaves pitted transversely with stomata. 

 The fruit is produced in terminal cones, composed of 

 numerous stalked peltate scales, each of which has, 

 on its under surface, a circle of sporangia, filled with 

 numerous uniform spores ; the spores have a spiral 

 covering, which when ripe breaks up into four clavate 

 hygrometric threads, called elaters."* The interior of 

 the stem is characterised by having a diaphragm of 

 vascular tissue dividing it at each joint ; this is seen 

 to be formed by a more or less distinct central pith 

 with an exterior fibrous cylinder, in which are usually 

 found two rows of longitudinal lacunae or meshes, 

 whicb seem to correspond with the furrows and 

 ridges of the stem. 



Let us compare with this description the structure 

 of a calamite. The trunk of a calamite was also 

 jointed, and bore scars along the joints from which 

 whorls of leaves, or leaf stalks proceeded. The stem, 

 however, was not hollow like that of the horsetail, 

 but solid, and consisted of a central pith, surrounded 

 by a woody cylinder, built up of scalariform vessels, 

 and having a thin cortical layer on the exterior with 

 lacunae or air cells, the intervening tissue containing 

 tubes marked with numerous pores. " The medulla 

 penetrated this cylinder by a series of regular wedges 

 which were continued as delicate lamince of one or 

 two cells in thickness to the cortical layer ; these cells 

 had their longest diameter in the direction of the 

 axis. The wedges were continuous and parallel 

 between each node. As the axial appendages were 

 produced in whorls, the only interference with the 

 regularity of the tissues was by the passing out through 

 the stem at the nodes of the vascular bundles which 

 supplied the leaves, and as the leaves were usually 

 opposite to the interspaces of the whorls above and 

 below, there was at each node a re-arrangement of 

 the wedges." + 



{To be continued^ 



Carruthers. 



t Ihhi. 



CHARLES DARWIN. 



BORN, FEBRUARY 12, S09. 

 DIED, APRIL 19, 1S82. 



FAR-reaching intellect, a mind serene, 

 Sublime in patience, fresh and evergreen ! 

 Thoughts sprang like flowers from a virgin soil, 

 But still he delved with unremitting toil. 

 Searched for his facts with microscopic eye, 

 With power to learn, and wisdom to apply. 

 From things familiar he enlarged his range. 

 Through truths before unknown, and passing 



strange. 

 Marked how the animate creation's strife 

 Improved the species, giving strength and life ; 

 Showed that the creatures which the most persist. 

 Are those the best selected to exist. 

 By means that Nature ever has at hand ; 

 Small each effect, but cumulative grand ! 

 Proved well each step before proceeding on, 

 Supplying links that make all Nature one. 

 Until all living things iu their relation 

 Led him from frequent up to one creation 

 With depth of insight, seer-like, to unfold. 

 Life's history from its dawn in days of old, 

 With glimpses of a future yet untold. 



Thoughts like to these had passed through human 



brain. 

 Before digested facts the truth sustain. 

 And though to some extent he missed the mark, 

 Much honour still is due to brave Lamarck, 

 For lacked he not the theory of selection. 

 Which to descent of creatures gives direction ? 

 Wisely, O Darwin ! thou thy work began, 

 And talked of species, when we thought of f?uin ! 

 Prepared foundations sure on which to build 

 Before unpleasant truth could be distilled. 

 For would proud man the information suit 

 To find he was descended from the brute ? 



Why waste a thought or even once repine 



To find our origin was un-divine ? 



'Twas, no doubt, pleasant for an earthly clod 



To think himself descended from a God ! 



As Alexander, when he grandly strove 



To prove his father was Olympian Jove, 



Though facts of Nature through which all are 



taught. 

 Show that the " wish was father to the thought." 

 Darwin has opened to the human mind 

 Ideal longings of another kind. 

 Sprung from the brute, yet with a feeling heart, 

 Man's destined still to fill a worthy part, 

 For SYMPATHY from history we find 

 Makes noble deeds and leavens all mankind. 



