44 



SCIENCE 



[Vol. XXI. No. 521 



and on the flanks of the Amethyst Mountain in the National Yel- 

 lowstone Park, the series, probably beginning as early as Laramie 

 age, is represented by an almost nnhroken succession of plant- 

 yieldiog deposits, extending upward into the Volcanic Tertiary, 

 where the ruins of vast Sequoian forests mantle the slopes with 

 their erect and prostrate trunks, among whose still persisting roots 

 of stone lie buried in great profusion the more delicate parts, 

 branches, leaves, fruits, and even flowers, of a rich and varied 

 flora. Thousands of beautifully preserved impressions of these 

 have been collected by Professor Knowlton and myself in two 

 field seasons' operations, besides a most extensive series of the 

 silicified wood, showing its internal structure as perfectly as if it 

 were still living. 



On the other side of the great continental divide, in California, 

 Oregon, and Washington, there are Miocene and still later de- 

 posits, in which have been found the later floras of the continent, 

 but whpse extent can as yet only be conjectured. Even in 

 Alaska there are great areas which have only to be scratched to 

 make them tell of oaks and willows and a great number of vege- 

 table forms that flourished there in late Tertiary time, the ana- 

 logues of which are now only found in the latitude of the States 

 and along the Atlantic border. 



Is it possible that botanists care nothing for all this? Do they 

 prefer to drudge upon the tissues of living plants to learn what may 

 be known by actually confronting the witnesses themselves of the 

 real character of the ancient vegetation of the earth and the true 

 lines along which it has developed? It cannot be. And yet such 

 would be the logic of their action. The truth is that institutions 

 of learning, much like the masses of mankind, are the votaries of 

 fashion. It is fashionable to found chairs of structural and 

 physiological botany, and it is fashionable to occupy them and 

 work out refined problems in the niceties of the science. Would 

 there were no worse fashions! "These ought ye to have done 

 and not to leave the other undone." The government has led the 

 way, through its several geological surveys, in establishing the 

 existence of these inexhaustible sources of botanical knowledge, 

 but it cannot, and probably should not, sustain the careful and 

 prolonged researches necessary to the solution of the many and 

 important scientiflc problems that naturally grow out of such a 

 mass of information. It can only use the data thus accumulated 

 in the settlement of the geological questions involved, and in the 

 development of the economic resources of the country to which 

 they serve as aids. The purely scientiflc results belong to the 

 higher institutions of learning to work out. It is true that only 

 the great and well-endowed ones can conveniently undertake this 

 work, but these are in condition to do so, and there is nothing 

 that could reflect greater credit upon an American university. 

 Such institutions make themselves a history by the original re- 

 search they foster and not by their pedagogic achievements. A 

 proper amount of teaching in the form of lectures growing out of 

 laboratory work is useful to give precision to such work as well 

 as to instruct, but it should never engross the energy of the teacher 

 to the exclusion of the chief object, the advancement of science. 

 In this case the materials are bulky and their collection and 

 transportation expensive, yet several leading Amei'ican colleges 

 have frequently indulged in this part of the expense, and then, 

 strangely enough, stopped there, and stored their cellars with un- 

 determined material ; or, if they have gone further, as at Princeton, 

 and been to the expense of installing the specimens in their 

 museums and employing a curator to take charge of them, they 

 only cumber their shelves with unnamed and unknown objects, 

 to he looked at as mere curiosities. 



To set forth any detailed plan for putting these suggestions into 

 practice would unduly prolong this article, but surely no one will 

 claim that the prosecution of paleobotanical research is impractica- 

 ble in a country that boasts of such universities as those at Chicago 

 and at Palo Alto. All that is needed is that its importance be 

 recognized; the task of reducing it to practice is only a matter of 

 administration. The diflSculty is to persuade educators to look 

 to value instead of custom in the encouragement of research. The 

 great energy that is devoted to small things is only less strange 

 than the little energy that is devoted to great things, and a new 

 and advanced spirit needs to be breathed into our higher education. 



The new botany is not merely the study of plants from the 

 paleontological side; it is their study from all sides and from all 

 points of view, and a school of botany in a great modern univer- 

 sity should no more limit itself to the facts that living plants present 

 thanaschoolof history should be narrowed down to the old method 

 of recounting the deeds of kings, dynasties, and warriois us con- 

 stituting all of human history. The Qiere "determination" of 

 fossil plants, although of course the most laborious part, is a com- 

 paratively unimportant part from the botanical standpoint. The 

 great work is their affiliation. As I have shown, we have in 

 America a succession of plant-bearing horizons not so widely 

 separated in time but that the later forms may be in large de- 

 gree afiiliated upon the next earlier ones, so that, in the right 

 hands, there is hope that something like a complete history of 

 plant development may be ultimately worked out. No grander 

 theme presents itself to the scientific world, and the time is ripe 

 for its inauguration. Hitherto the study of fossil plants has been 

 conducted wholly from the geological standpoint, and. as I have 

 been obliged to insist,' this does not necessarily involve the correct 

 systematic determination of fossil forms, provided their identity 

 can be surely recognized wherever found. A new method is there- 

 fore loudly called for, by which far greater certainty than here- 

 tofore can be reached in establishing the real nature and affinities 

 of extinct floras. In other words, they must be studied from the 

 botanical standpoint and all the light brought to bear upon them 

 that the known flora of the whole globe is able to shed. This is 

 no simple task, it is one that demands the highest ability and the 

 widest facilities. But thus pursued, with sufficient time, patience, 

 and labor, its success is cei'tain, and its value beyond calculation. 



THE STRUCTURE OF INSECT TRACHEA, WITH SPECIAL 

 REFERENCE TO THOSE OF ZAITHA FLUMINEA. 



BT DR. ALFRED 0. STOKES, TRENTON, N.J. 



The following paper has a threefold purpose. First, to confirm 

 an important discovery made in this country, but, so far as I have 

 been able to learn, never corroborated in any American publica- 

 tion. It was Professor George Macloskie of Princeton College 

 who announced in The American Naturalist for 1884. page 567, 

 that the so-called spiral threads of insect tracheae are in reality 

 chitinous folds of the membrane, and consequently tubules, which 

 are longitudinally fissured. Professor A. S. Packard, in the same 

 magazine for 1886, page 438, in a paper "On the Nature and 

 Origin of the So-Called Spiral Thread of Tracheae," says, " All the 

 figures of the spiral thread hitherto published I believe to be in- 

 correct," adding in a foot-note that " Thus far I find myself un- 

 able to agree with Professor G. Macloskie that the ' spirals of the 

 proper trachese' are ' crenulated thickenings of the intima,' or 

 that the tsenidia are really tubular " Unless I have overlooked 

 some more recent American contribution to the literature of the 

 subject, this is the latest statement, with the single exception 

 of a short note from Professor Macloskie himself published 

 in a receut number of Science, in which communication his 

 former conclusions are re-affirmed, as the result of another 

 examination of the so-called spirals. But, although Dr. Pack- 

 ard does not accept these conclusions, he suggests the word 

 "taenidium" as a name descriptive of the solid thread, as it is 

 generally considered to be, a name which it may be well to adopt, 

 but with a meaning somewhat different from that attached to it 

 by its learned inventor, who considers the objects which the 

 word describes "to be separate, independent, solid rings, more 

 or less parallel and independent of each other, . . . usually thin, 

 flat, but often concavo-convex, the hollow looking toward the 

 centre of the tracbese." 



Some months ago my correspondent, Mr. Fr. Dienelt of Loda, 

 Illinois, sent me a microscope slide of the tracheae of the not un- 

 common aquatic bug Zaitha fluminea. for a purpose to ba specially 

 referred to hereafter, but one that had no connection with the 

 structure of the teenidia ; and, still more recently, at my request, 

 Mr. B. F. Quimby of Chicago collected in Jackson Park, in that 

 city, several specimens of the same insect and kindly sent them 



1 American Geologist, vol, Ix., January, 1892, pp. 39-40. 



