May i6, 1895] 



NA TURE 



5: 



i)f hydrogen, are spectroscopically invisible in the sun and stars — 

 though they doubtless exist there — and that these new gases 

 scarcely yet glim[ised, have already, in all probability, supplied 

 us with many ]5oints of contact between our own planet and the 

 hottest part of our central luminary that we can get at, and stars 

 like Bellatrix, are full of hope for the future, not only in relation 

 to the possibility of more closely correlating celestial and ter- 

 restrial phenomena, but in indicating that a terrestrial chemistry 

 founded on low density surface products in which non-solar gases 

 largely enter, is capable of almost infinite expansion when the 

 actions and reactions of the new order of gases, almost, it maybe 

 said, of paramount importance in certain stages of stellar evolu- 

 tion, shall have been completely studied. 



With regard to the differences indicated between the results 

 of the chromospheric and eclipse observations in the above 

 table, it may be useful to remark that Prof. Young's " fre- 

 quencies," invaluable though they are, must necessarily be of 

 less importance, from the present point of view, than the eclipse 

 observations obtainerl, il may almf)Sl be said, at the same instant 

 of lime. There may be, and doubtless are, two perfectly 

 distinct causes for the appearance of the so-called chromospheric 

 lines. First, the tranquil condition of the lower strata of the 

 sun's atmosphere which gives us the pure spectnmi produced at 

 a constant — and the highest that we know of in the sun — tempera- 

 ture. Secondly, the disturbed condition which fills the spectrum 

 with lines of a so-called prominence. Formerly it was univers- 

 ally imagined that the prominences were shot up from below ; 

 and in that case the lines added would indicate a temperature 

 kighsr than the normal. But I have sent many papers in to the 

 Society indicating the many arguments against this view,^ and to 

 me, at the present time, this view is almost unthinkable. If 

 these disturbance-lines are produced from above, they may repre- 

 sent the effects of many stages of lower temperature. Hence a 

 list of chromospheric lines loses most of its value unless the 

 ct»nilitions of each observation are stated, and the phenomena 

 appearing at the same place at the same instant of time are 

 recorded. 



Now, this .same place and same time condition is perfectly met 

 by eclipse photographs, and hence I attac i a great value to 

 them. But the ct)m[)arison lietween such eclipse observations 

 and the spectra of certain stars indicates that the latter in all 

 proljability afford the best criteria of all. 



THE MARQUIS OF SAPORTA. 



T N the study of paUvobotany we may concern ourselves 

 ^ with the various problems of distribution, the geologic 

 sequence of plant types, the \alue of fossil plants in com- 

 parative stratigraphy, and as tests of climatic conditions ; 

 or our attention may be concentrated on the important 

 facts revealed by a microscopic study of petrified plant 

 tissues. The latter field of research, in which Prof 

 Williamson has laboured with remarkable success during 

 the last twenty-five years, is gradually being recognised 

 by botanists as a branch of their science which they 

 cannot afford to neglect in dealing with the wider pro- 

 blems of plant life. Fascinated by the almost incredible 

 perfection in which I'akcozoic, and more rarely Mcsozoic, 

 species have been preserved, the student of vegetable 

 morphology is apt to take too little heed of the wealth 

 of material which can only be studied in the form of 

 structureless casts or impressions. In the majority of 

 fossil floras the geologist or botanist must perforce confine 

 himself to an examination of the few isolated and im- 

 perfect fragments that have escaped destruction in the 

 process of denudation and rock-building, and have been 

 preserved by fossilisation as meagre representatives of 

 a past vegetation, .^s a specialist in this latter branch 

 of pakeobotany, there has been no more ardent worker 

 since the days of Adolphe Brongniart, whom we may 

 regard as the founder of |)aI;vobotanical science, than the 

 Marquis of Saporta. .Saporta's recent death, at his home 

 in .\ix-en- Provence, at the age of seventy-two, has de- 

 prived botanical and geological science of anunusually 

 able and vigorous worker. 



* They .ire set oiil .it length in the "Chemistry of the Sun," which I 

 puhlished in 1887. 



A perusal of Saporta's numerous contributions to- 

 scientific literature affords abundant evidence of critical 

 and detailed investigation during a long period of years ; 

 nearly the whole of his published work has been in the 

 domain of fossil botany. The Tertiary vegetation of 

 France forms the subject of several of his contributions 

 to science. From an early stage of his career the Caino- 

 zoic plant-bearing strata of Provence have occupied a 

 prominent position in his pakeobotanical studies ; the 

 Eocene flora of Aix, a valuable monograph on the 

 remnants of an Eocene flora preserved in the tuffs of 

 S&anne, and various other writings on Tertiary plants, 

 bear eloquent testimony not only to a remarkable power 

 of detailed systematic work, but to a striking aptitude 

 for a broad and philosophic manner of treatment. 

 Students of Mesozoic botany soon learn to appreciate 

 Saporta's memoirs on Cretaceous and Jurassic plants, 

 and especially the splendid series of monographs on the 

 Jurassic flora of France, published as separate volumes 

 of the " Pale'ontologie Franqaise" from 1873-91 ; in this 

 profusely illustrated work, dealing primarily with P'rench 

 vegetation, we have to a large extent a g^eneral hand- 

 book of Oolitic botany. One feature which sets a high 

 value on Saporta's pakeobotanical work, is his wide 

 and thorough acquaintance with the facts of distribution 

 and taxonomy of living plants. Pateontological records 

 are often in themselves of no special interest to zoologists 

 and botanists, but if interpreted as indices of plant 

 distribution in past ages, and applied to the wider 

 problems of the evolution and dissemination of plant 

 types, they assume considerable importance. .Saporta's 

 knowledge of recent floras, and his keen enthusiasm as an 

 evolutionist, led him to regard fossil plants not simply as 

 convenient aids to the stratigfaphical geologist, but as 

 aflbrding indispensable data to the student of plant 

 phylogeny. In " Le Monde des plantesavant I'apparition 

 de I'homme " (Paris, 1879), we have a series of articles 

 originally published in the Rci'uc ties Deux Mo>2iiis and 

 Lu jVii/un; in which .Saporta's encyclop;edic information 

 and finished literary style combine to render attractive to 

 the layman and the specialist a retrospect of plant life 

 during the geologic ages. Unfortunately the elaborate 

 frontispiece to this volume, described as the " oldest known 

 land plant," and named Et^pleris Mornrei. is merely a 

 representation of an iron pyrites infiltration on the surface 

 of a .Silurian slate, and cannot be retained as a plant 

 impression. In a more recent and smaller volume, 

 " Origine paleontologique des arbres cultives ou utilises par 

 I'homme" (Paris, 1888), we have an interesting sketch of the 

 geological history of existing forest trees : and in another 

 and more ambitious work,' in collaboration with Prof 

 Marion, an attempt is made to follow the lines of descent 

 of the several subdivisions of the vegetable kingdom. The 

 pala'obotanist who is bold enough to \enture on the task 

 of tracing out the ancestry of plant forms, and of attack- 

 ing the problems of development, is exposed to the very 

 serious danger of allowing unsound links to form part of 

 his chains of life. Saporta's constant desire to treat 

 fossil plants from the point of view of a sanguine evo- 

 lutionist, who wishes to press into his ser\ ice all possible 

 pieces of evidence towards the better understanding of 

 the process of plant e\olution, has in certain instances 

 been led beyond the limits of accurate scientific reasoning. 

 The majority of the so-called fossil alg;e. to which he has 

 devoted considerable attention, have been put out of 

 court by Nathorst and others, as ha\ ing no claim to con- 

 sideration as records of thallophytic life . and it is generally 

 agreed that the value of his work in this direction is 

 seriously discounted, by the more than doubtful specimens 

 which arc described as vestiges of the lower and more 

 primitive foniis of plants. .\ few months before his 

 death, Saporta completed an exhaustive monograph on 



NO. 1333, VOL. 52] 



1 Saporta and Marion : 

 81-1885. 



.'^volution tlti rcgne veg^ta!." 



