April 7, 1892] 



NATURE 



549 



cells become absorbed. In C. glauca and Rumphiana tracheides 

 are formed, analogous to the elaters of the Hepaticae ; their func- 

 tion is uncertain. The megaspores, or embryo-sacs, of which 

 there are usually from sixteen to twenty, lengthen in the direction 

 of the chalaza, some of them sometimes penetrating and forming 

 " tails " between the elements of the fibrovascular bundle of the 

 funicle. The sister-cells of the embryo-sacs, instead of being 

 absorbed at an early period, as in other Angiosperms, disappear 

 only much later. The megaspores which develop fully divide at 

 the end into two or three cells, which are in most cases naked, 

 and result from the division of a single cell. In the great 

 majority of cases only a single megaspore in each nucellus has 

 these terminal or sexual cells furnished with cell-walls ; this is 

 the future embryo-sac. The oosphere is always formed from 

 the sexual cell which has the thickest wall. No antipodals are 

 formed. 



Only a single ovule is ever fertilized, and the pollen-grain 

 which fecundates it advances towards the embryo-sac in a way 

 entirely difTerent from anything that occurs in other Phanero- 

 gams. The pollen-tube does not enter the ovarian cavity ; it 

 descends the stylary cylinder, crosses the bridge and the tissue 

 which unites the ovule with the wall of the ovary, and arrives at 

 the fibrovascular bundle which leads to the chalaza, where it 

 produces two short branches, then traverses the chalaza, and 

 enters the ovule by means of the " tail" of a sterile megaspore, 

 and continues its course towards the embryo-sac. Towards the 

 middle of the nucellus it contracts, tapers off, and ruptures, the 

 terminal fecundating portion becoming separated from the rest 

 of the pollen-tube. This portion, which has a thickened wall, 

 and contains distinct protoplasm, never enters the micropyle or 

 the embryo-sac, but becomes firmly attached to the wall of the 

 latter, at a spot variable in position, but always at some distance 

 from the sexual apparatus. Dr. Treub has not, at present, been 

 able to detect in this portion a definite nucleus, or to follow the 

 actual process of fecundation. During the development of the 

 embryo-sac, numerous endosperm-nuclei are formed, and subse- 

 quently the embryo makes its appearance. The mode of de- 

 velopment of the embryo does not differ from that which occurs 

 in other Dicotyledons. 



The peculiar processes which accompany the act of fecunda- 

 tion, and the presence of a large number of megaspores, each 

 containing a sexual apparatus, induce Dr. Treub to regard the 

 Casuarinaceae as a distinct group of Angiosperms, of equal rank 

 with the Monocotyledones and Dicotyledones together, and he 

 proposes the following primary classification of Phanerogams : — 



I. Gymnosperms. 

 II. Angiosperms. 



A, Chalazogams (Casuarinacex). 



B. POROGAMS. 



1. Monocotyledones. 



2. Dicotyledones. 



The Chalazogams are not intermediate between Gymno- 

 sperms and Angiosperms, but occupy an isolated and inferior 

 position among the latter, somewhat analogous to that of 

 Lycopodium among Vascular Cryptogams. The paper is illus- 

 trated by 21 fine plates. A. W. B. 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE. 



Oxford. — Endo-wment of Original Research. — The following 

 notice has been received by the Vice-Chancellor: — A gentle- 

 man has established a Scholarship of £ioo, tenable for one 

 year, for the encouragement of original research. The Scholar 

 will be selected by a Committee composed of Dr. George Thin, 

 Surgeon-General Cornish, and Prof. A. Winter- Blyth. The 

 conditions of the Scholarship are, that the research be on a 

 subject requiring for its elucidation both chemical and bacterio- 

 logical methods, and the subject will be selected by the Com- 

 mittee of Selection. With the concurrence of the Scholar, the 

 work is to be done in the laboratories of the College of State 

 Medicine, loi Great Russell Street, W.C., and the Scholar will 

 have to devote his whole time to the work. Application to be 

 made to Surgeon-General Cornish, on or before April i8, 1892. 



In a Convocation held on April 5, it was decreed (the 

 Council of the Royal Geographical Society having offered a 

 further sum of £iSo a year, to be met by an equal sum from 

 the University, for the payment of a Reader in Geography 



NO. I 171, VOL. 45] 



during the next five years) that the offer be accepted, and fhaj. 

 the thanks of the University should be conveyed to the Couaci 

 of the Royal Geographical Society for their liberal offer. 



The programme of the fifth summer meeting of University 

 Extension and other students, to be held in Oxford in July and 

 August 1892, has been issued, and in its general character 

 resembles that of last year. The inaugural lecture will be de- 

 livered by Mr. John Addington Symonds (if his health permits) 

 on Fiiday, July 29, at 8.30 p.m. The meeting will, as in 

 former years, be divided into two parts, viz. from July 29 to 

 August 9, and from August 10 to August 26. In Natural 

 Science the following arrangements have been made : — 



In Chemistry : a course of eighteen days' practical instruction 

 in the University laboratory, limited to 100 students, conducted 

 by Messrs. J. E. Marsh and A. D. Hall of Balliol College. 



In Geology : a special course of fourteen days' practical in- 

 struction, with field work provided, if at least 40 students offer 

 themselves. 



In Botany : in addition to lectures on primroses and their 

 relations, it is proposed to arrange, for a class of not less than 

 40 students, a three weeks' course of practical instruction. 



In Biology : to the same minimum number of students is 

 offered a special course of lectures and demonstrations in the 

 physiological laboratory, to form an introduction to the study 

 of life, and especially of nervous organisms. 



Courses of lectures and instruction on Astronomy, Mechanics, 

 Sound, Light and Heat, Electricity, Physiography, and Hygiene 

 can be arranged. 



It is also announced that there will be no summer meeting 

 in 1893, ^s during August in that year the Examination Schools 

 will be in the hands of workpeople. 



St. Andrews. — Summer Session. — A course of lectures in 

 zoology and botany, qualifying for graduation, will commence 

 on May 2, the former by Prof. Prince, the latter by Mr. Robert- 

 son, the University Lecturer on Botany. These are open to 

 students of either sex. 



SOCIETIES AND ACADEMIES. 

 London. 



Royal Society, March 31. — "Aberration Problems: a 

 Discussion concerning the Connection between Ether and 

 Matter, and the Motion of the Ether near the Earth." By 

 Oliver Lodge, F.R.S., Professor of Physics, University College, 

 Liverpool. 



The paper begins by recognizing the distinction between ether 

 in fi'ee space and ether as modified by transparent matter, and 

 points out that the modified ether, or at least the modification, 

 necessarily travels with the matter. The well-known hypothesis 

 of Fresnel is discussed and re-stated in modern form. 



Of its two parts, one has been verified by the experiment of 

 Fizeau, the other has not yet been verified. Its two parts are, 

 (i) that inside transparent matter the velocity of light is affected 

 by the motion of that matter, and (2) that immediately outside 

 moving matter there is no such effect. The author proceeds to 

 examine into the truth of this second part, (i) by discussing what 

 is already known, (2) by fresh experiment. 



The phenomena resulting from motion are four, viz.: — 



(i) Changes in direction, observed by telescope and called 

 aberration. 



(2) Change in frequency, observed by spectroscope and 

 called Doppler effect. 



(3) Change in time of journey, observed by lag of phase or 

 shift of interference bands. 



(4) Change in intensity, observed by energy received by 

 thermopile. 



After a discussion of the effects of motion in general, which 

 differ according as projectiles or waves are coniemplated, the 

 case of a fixed source in a moving medium is considered ; then of 

 a moving source in a fixed medium ; then the case of medium 

 alone moving past source and receiver; and, finally, of the 

 receiver only moving. 



It is found that the medium alone moving causes no change 

 in direction, no change in frequency, no detectable lag of 

 phase, and probably no change of intensity ; and hence arises 

 the difficulty of ascertaining whether the general body of the 

 ether is moving relatively to the earlh or not. 



A clear distinction has to be drawn, however, between the 

 effect of general motion of the medium as a whole, and motion 



