AND OF THE PHYSICAL SCIENCES. 



99 



t^ned respecting tlieir powers and courage ; but there is good reason to believe, that 

 the Sea Eagle does not often subject itself to much danger from temerity. 



It beo-ins to construct its nest sometime in March, and the young are abroad about 

 the middle of Auf^ust. The diameter of the nest is about five feet, and it consists of 

 twigs, heath, sea-weed, dry grass, and other materials of a like nature, arranged in 

 a slovenly manner. There are generally two eggs, sometimes only one. They are 

 about the size of those of a goose, but shorter, and of a yeliowish-white colour, with 

 a few reddish dots at the large end. The young are fed with fish, carrion, grouse, 

 and young sea birds. 



Great numbers of Eagles are annually destroyed in Scotland, oji account of the 

 depredations which they commit among the lambs ; yet there is little probability of 

 their beinf' extirpated in the northern parts of that country, although very few re- 

 main in the south. Dr Buphnan, writing in 1834, doubts whether a pair is to be 

 found wild in Dumfries-shire, or more than a dozen in Galloway. This species is 

 less frequently seen in captivity than the Golden Eagle, probably because its haunts 

 are more remote from the densely peopled parts of the country. An interesting ac- 

 count is given of a captive Eagle, in Ma?gillivray's Rapacious Birds of Great Britain, 

 by its owner, Dr Neill, who has kept it since the autumn of 1827. 



Habits of the Blue-backed Dove {Columha Q£nas). — In *' The Naturalist 

 for May, Mr Salmon gives the following interesting notice on this subject : — *' I have 

 lately been asked if I can suggest a better name than Stock or Wood Pigeon for the 

 Cohanba (Enas of authors. The provincial name in this district is Sand Pigeon, 

 which I cannot but consider fuUy as appropriate as Bank Swallow, applied in conse- 

 quence of the situation the bird selects for nidification. Those who live in woody 

 districts, however, might object to this specific designation, as the bird would then, 

 in all probability, breed in woods ; but of this I am not certain. I am inclined to 

 suspect that the species is very local in its distribution in this country during the 

 breedin<T season, and that it is only towards its autumnal migration that it is seen in 

 very great numbers in the woodlands. I have known an instance of its breeding in 

 the topmost branches of the Scotch Fir, in a similar manner to the Ring Pigeon 

 (Columba Palumhus), which is a true arboreal species, and might, with great pro- 

 priety, be called Wood Pigeon. Indeed, the latter is given by Selby as a provincial 

 name, by which also it is always known in this county. If it be found necessary to 

 make any alteration in the nomenclature of the British Pigeons, I should be dis- 

 posed to name them thus : — Wood Pigeon, Columba Palumbus ; Sand Pigeon, C 

 arenea ; Rock Pigeon, C. Livia." Our mode of nomenclature differs, and we should 

 nrei'er naming them thus: — Columba Palumbus, Ringed Dove, or Wood Pigeon; 

 C. Livia, Rock Dove, or White-backed Pigeon ; C. (Enas, Blue-backed Pigeon ; 

 C. Turtnr, Ring-necked Turtle Dove. But there is no end to alterations of this 

 kind, chiefly because names are imposed at first without consideration, and altered by 

 persons destitute of judgment, or, if possessing that quality, deficient in the necessary 

 knowledge of species. 



Arrival of Birds in the present Spring. — Notwithstanding the severity of 

 the weather, the Wheatear was seen in the King's Park, early in April, and by the 

 end of the month was common. Hirundo rHstica was seen at Newington on the 29th 

 April. Cypselus murarius, Hirundo rustica, Hiruudourbica, and IHnmdo riparia, 

 were observed at Canonmills on the 1st May. Sylvia Trochilus was shot at Roslyn 

 on the 29th April. Turdus torquatus was observed near Swanston on the Pentland 

 Hills on the 4th i\Iay ; and on the same day, two Cuckoos were seen on Dahnahoy 

 Hill. Totanus hypohucos occurred at Roslyn on the 29th April, but bad probably 

 arrived several weeks before. 



BOTANY. 



M. Dutrochet's Observations on the Sleep of Plants. — Continued from 

 last Number, 



Tfe flowers above described expand and close only once, after which the death 

 of the corolla takes place. I shall now examine the flowers which alternately open 

 and shut for several days in succession, taking the Dandelion, Leontodon Taraxa- 

 cum, as an example. The flower of this plant generally lives ten days and a half, 

 having during that period its expansion in the morning, and its sleep in the evening. 

 Its last sleep takes place in the middle of the day, and is followed by the death 

 of the corollas. In the state of waking, the scmiflorets of which this flower is com- 

 posed curve outwards, producing its expansion ; and in sleep curve inwards, effecting- 

 its closing. Although these semiflorets ai-e very thin, I have with the microscope 

 observed the internal organization of their nerves, which are very small, and four 

 in number in each. At the inner or upper surface of each of its nerves there is 

 a cellular tissue disposed in Unes, of which the cellules are covered with Mobules, 

 and which is exactly similar to that which I have observed in the nerves of the 

 corolla of Mirabilis. At the outer or lower surface of the nerves of the semifloret 

 is a very thin layer of fibrous tissue situate between a layer of trachcoi and a 

 layer of cellules filled with air, and placed superficially. This fibrous tissue, in ail 

 respects similar to that which exists in the nerves of the corolla of Mirabilis, is 

 in like manni^r included between two layers of pneumatic organs. It is therefore 

 probable that this fibrous tissue is incurvable by oxygenation, and that the cellular 

 tissue is incurvable by eudosmosis, just as is the case with the nerves of the corolla 

 of Mirabilis. And in fact, observation shows that the incurvation which produces 

 the wake of the semiflorets of the Dandehon is owing to the imnletion of the cel- 

 lules with fluid to excess ; in other words, to eudosmosis, and that the incurvation 

 which produces sleep is owing to oxygenation. Tae semiflorets of the flower of 

 the Dandelion being gathered early in the morning, while they are still in the state 

 of sleep or cui'ved inwards, and being immersed in aerated water, assume the op- 

 posite incurvation, or curve outwards. This takes place in darkness as well as in 

 light. If they are immersed in unaerated water, they curve outwards to excess 

 and so remain. If these semiflorets, thus curved, are placed in syrup, they assume 

 the opposite curvature ; and, on being placed in pure water, resume the outward 



curve. Thus, there can be no doubt that endosmosis produces this action. If semi- 

 florets, in the state of waking, are left for some hours in aerated water, they then 

 assume an inward cui've, or that of sleep ; and this curve is not altered by transport- 

 ing them into syrup, which proves that the incurvation of sleep is owing to oxygena- 

 tion. Thus, the wake and sleep of the semiflorets of the flower of the Dandelion 

 result from the alternately predominating incurvation of an organic tissue incurvable 

 by endosmosis, and of an organic tissue incurvable by oxygenation. The first is un- 

 doubtedly the cellular tissue, and the last the fibrous tissue, both contained in the 

 nerves of the semifloret. These two incurvable tissues, according as the one prevail* 

 over the other, expand or close the flower. 



The causes which render predominant the morning incurvation of the cellular 

 tissue, or agent of waiting, are, on the one hand, a more powerful ascent of the sap 

 under the influence of light, which increases the turgescence of this tissue ; and, on 

 the other hand, the diminution of the antagonist force of incurvation of the fibrous 

 tissue, which is the agent of sleep, and which takes place at night. In fact, if the 

 semiflorets are gathered in the evening when they have assumed the incurvation of 

 sleep, and immersed in oxygenated water, they there retain without change their in- 

 curvation; but if, next morning, there be plucked from the same flower other semi* 

 florets which still retain the incurvation of sleep, and if they be immersed in aerated 

 water, they instantly assume the incurvation outwards, even in the dark. Now, by 

 immersing the semiflorets in water, endosmosis of their cellular tissue is excited, and 

 so its incurvation is effected, producing the state of waking or expansion. If this 

 result does not take place in the evening, it is because the incurvation by oxygena- 

 tion of the antagonist fibrous tissue is too strong, and cannot be overcome by the in- 

 curvation of the cellular tissue. If by immersing next morning in water the semi- 

 florets which have passed the night on the plant, their outward incurvation is 

 produced, this proves that the force of incurvation of the fibrous tissue has diminished, 

 and that, in consequence, this fibrous tissue has lost in the course of the night a part 

 of its oxygenation ; so that the cellular tissue, incurvable by endosmosis, which is its 

 antagonist, and which is the agent of the wake or expansion of the flower, then pre- 

 dominates. 



Thus the flower which during several days presents the alternations of waking and 

 sleep, is that in which the fibrous tissue, the agent of sleep, loses during the night a 

 part of the oxygen which has been fixed in its interior in the course of the day, and 

 which is the cause of its incurvation ; so that this latter having in the morning lost 

 its strength, the cellular tissue, which is incurvable by endosmosis, and is the agent 

 of expansion or waking, becomes again predominant. The sleep of this flower takes 

 place anew in the evening, because the oxygenation of the fibrous tissue, the agent 

 of sleep, gradually increases during the day, and at length renders its incurvation 

 victorious ; at the same time, the diminution of the light occasions a diminution of 

 the ascent of the sap, which weakens the turgescence, and consequently the incurva- 

 tion of the cellular tissue, which is the agent of expansion or waking. These alter- 

 nations cease only with the death of the corolla. The flowers which have only a 

 single expansion and a single closing, or which wake and sleep only once, are those 

 whose single sleep is immediately followed by the death of the corolla. 



The entire flower of the Dandelion, if immersed when expanded in unaiirated 

 water, deprived of communication with the atmosphere, remains in the same state 

 v.ithout change. If the water is in contact with the atmosphere, it takes up air in 

 solution, and the flower immersed in it assumes the state of sleep in two or three 

 hours. 



It may with propriety be remarked, that these experiments confirm what I have 

 said in my Essay on the Respiration of Plants, namely, that vegetables respire like 

 animals, by assimilating oxygen, of which the presence in the organic tissue is as 

 necessary in the one as in the other order of beings. 



Pines of North California. — The following note is extracted from the 

 " Companion to the Botanical, Register," in which a biographical account of the 

 late Mr Douglas is given : — '* About an hour's walk from my camp, I met an In- 

 dian, who, on perceiving me, instantly strung his bow, placed on his left arm a sleeve 

 of Racoon skin, and stood on the defensive. Being quite satisfied that this conduct 

 was prompted by fear, and not by hostile intentions, the poor fellow having probably 

 never seen such a being as myself before, I laid my gun at my feet on the ground, 

 and waved my hand for him to come to me, which he did slowly, and with great cau- 

 tion. I then made him place his bow and quiver of arrows beside my gun, and strik- 

 ing a light, gave him a smoke out of my own pipe, and a present of a few beads. 

 M'ith my pencil I made a rough sketch of the Cone and Pine-tree which I wanted 

 to obtain, and drew his attention to it, when he instantly pointed to the hills fifteen 

 or twenty miles distant towards the soutii ; and when I expressed my intention of going 

 thither, cheerfully set about accompanying me. At mid-day I reached my long- 

 wished-for Pines, and lost no time in examining them, and endeavouring to coliect 

 specimens and seeds. New and strange things seldom fail to make strong impres- 

 sions, and are therefore frequently overrated ; so that, lest I should never again 

 see ray friends in England, to inform them verbally of this most beautiful and im 

 mensely grand tree, I shall ht^re state the dimensions of the largest I could find 

 among several that had been blown down by the wind. At three feet from the 

 ground its circumference is 57 feet 9 inches; and at 134 feet, 17 feet 5 inches; 

 the extreme length 245 feet. The trunks are uncommonly straight, and the bark 

 remarkab-y smooth for such large timber, of a whitish or light-brown colour, and 

 yielding a great quantity of bright amber gum. The tallest stems are generally un- 

 branched for two-thirds of the height of the tree ; the branches rather pendulous, 

 with cones hanging from their points like sugar loaves in a grocer's shop. These 

 cones, however, are seen only on the loftiest trees, and the putting myself in posses- 

 sion of three of them (all I could obtain), nearly brought my life to a close. As it 

 was impossible either to climb the tree or hew it down, I endeavoured to knock off 

 the cones by firing at them with ball, when the report of my gun brought eight In- 

 dians, all of them painted with red earth, armed \7ith bows, arrows, bone-tipped 

 spears, and flint-knives. They appeared any thing but friendly. 1 endeavoured to 

 explain to them what I wanted; and they seemed satisfied, and sat down to smoke. 



