CIRCUMNUTATION. 



COCKBURN, ALEXANDER J. E. 



flower, when touched, toward the pistil; since 

 the organs exhibit no signs of circumnutation, 

 remaining perfectly still unless excited. The 

 curling of the tip of the tendril of a vine upon 

 touching it seems to be unconnected with the 

 regular circumnutating movement of the or- 

 gan, as the extremity of the tendril does not 

 appear to participate in circumnutation, which 

 has its seat in the base and lower portion of the 

 tendril. There are a number of specialized 

 functions of occasional or rare occurrence which 

 seem to be peculiar modes and amplifications of 

 the universal circumnutating motion acquired 

 by natural selection for special purposes Such 

 are the phenomena of the straightening or 

 drooping of the flower - peduncles after the 

 flower has withered, by which the seeds can be 

 deposited or scattered to the best advantage. 

 A certain species of clover (Trifolium subter- 

 raneuni) possesses the singular property of 

 burying its seed-pods in the soil by a strongly 

 geotropic action of the flower-peduncles, the 

 three or four perfect flowers of the head curv- 

 ing downward against the peduncle by epi- 

 nasty, and the central aborted flowers forming 

 stiff, claw-like projections, which are pressed 

 into the ground by the geotropic bending and 

 lengthening of the peduncle, aided by the rock- 

 ing movement of circumnutation, and which 

 ultimately recurve themselves, dragging the 

 head underneath the soil. The gynophores of 

 the peanut-vine penetrate the ground in a 

 similar manner, actively circnmnutating. The 

 seeds of these plants do not become fertile un- 

 less thus buried. The Amphicarpcea monoica 

 emits branches which pierce the ground and 

 produce flowers and pods. The movements 

 of plants due to epinasty or hyponasty, which 

 have been proved to be modifications of cir- 

 cumnutation, are of the most manifold diver- 

 sity, and the purposes subserved by them ex- 

 ceedingly various and divergent. In some 

 cases circumnutation takes place in sudden 

 vibratory steps. If the hypocotyls of the cab- 

 bage, the joints of grasses, and the leaves of 

 the DionfRa are viewed under a microscope, 

 they are seen to jerk forward for a distance of 

 001 or '002 inch every few seconds, and then 

 recede for a portion of the distance gained. 

 The retreating movement is probably occa- 

 sioned by the elasticity of the resisting tissues. 

 Circumnutation depends upon a more rapid 

 growth or an increased turgescence on one side 

 of an organ, followed by a like increase in the 

 growth or extension of the cells of another 

 part usually almost the opposite side. The seat 

 of this spasmodic extensibility or growth travels 

 about to every part of the surface in succession. 

 This continued action causes the outer portions 

 of the organ to describe a series of irregular 

 ellipses, with their longer axes directed to all 

 points of the compass. The path of any point 

 of the oscillating organ is more correctly de- 

 scribed as a spiral line, since the part is con- 

 tinually growing. These revolutions are far 

 from being regular. The path during an os- 



cillation is sometimes in lines comparatively 

 direct, sometimes quite curved; its character 

 is apt to change at any time, and sometimes the 

 general movement is interrupted temporarily, 

 and little intermediate loops or triangles are 

 formed. The periodicity in the growth of the 

 cells and the alternating expansion and incre- 

 ment in the different parts of the organ is per- 

 haps due to the need of the cells for periods of 

 rest. All the movements of plants which are 

 proved to be accompanied by the swerving mo- 

 tions which distinguish circumnutation, and are 

 produced by the alternate turgescence of the 

 cells in different parts of the organ, are sup- 

 posed by Darwin to be modified forms of cir- 

 cumnutation evolved under the action of various 

 stimuli which are beneficial in their effects, in 

 accordance with the law of natural selection. 



COCKBURN, THE RIGHT HONORABLE SIR 

 ALEXANDER JAMES EDMUND, Baronet, the Lord 

 Chief-Justice of England, Privy Councilor, 

 Knight of the Grand Cross of the Order of the 

 Bath, was born in 1802. He was the son of 

 Mr. Alexander Cockburn, formerly Minister to 

 Colombia. His mother was Yolande, daughter 

 of Vicomte de Viguier, of Saint Domingo. He 

 was descended from an ancient family. the Cock- 

 burns of Langton. He was nephew to Admiral 

 Sir George Cockburn, who took part in the 

 destruction of Washington during the War of 

 1812. He succeeded to the baronetcy on the 

 death, in 1858, of another uncle, Sir William, 

 the ninth baronet. 



He was educated at Trinity College, Cam- 

 bridge, where he graduated LL. B. in 1829. 

 After a brilliant university career he received 

 a Fellowship. Mr. Cockburn was called tc 

 the bar at the Middle Temple, and went on the 

 Western Circuit in 1829. In 1841 he became a 

 Queen's Counsel. A volume of reports on the 

 most important cases springing out of the Re- 

 form Bill of 1832 increased his reputation, and 

 gave him practice before the Election Commit- 

 tee. In 1834 he was appointed on the Municipal 

 Corporation Committee. During the railway 

 mania of 1846, when Parliament authorized the 

 construction of lines costing 130,000,000, he 

 obtained a lucrative share of the Parliamentary 

 practice in regard to them. 



At the general election of 1847 he was re- 

 turned as Liberal member for Southampton. 

 He did not distinguish himself in debate until 

 1850, when he made his eloquent defense of 

 Palmerston's foreign policy in a memorable 

 speech on the Pacifico question. Don Pacifico 

 was a Portuguese Jew, resident in Athens, but 

 born in Gibraltar, and therefore a British sub- 

 ject. The Athenians, in deference to a request 

 of the Rothschilds, were forbidden to continue 

 an annual custom of burning Judas Iscariot in 

 effigy. They revenged themselves by sacking 

 the house of Don Pacifico, who asked for dam- 

 ages amounting to about 30,000. Lord Palm- 

 erston added to this some other petty claims, 

 and made a demand on the Hellenic Government 

 for instantaneous restitution. The Foreign 



