NATURE 



429 



THURSDAY, SEPTEMBER 26, 1872 



BALFOUR'S, PAL^ONTOLOGICAL BOTANY 



Introduction to the Study of Pahvontological Bjt luy. 

 By J. H. Balfour, A.M., &c.. Professor of Botany, Edin- 

 burgh. (Edinburgh: Adam and Chas. Black, 1872.) 



TH E mastery of an alphabet by a child depends on 

 his recognising and remembering the differences in 

 form of the various arbitrary signs which we conventionally 

 use to represent different sounds. Perhaps in the face of 

 the alphabetic researches ol iVIr. John Evans we should 

 withdraw the qualification — arbitrary. He may see a con- 

 nectioa between the sign and the sound, and be able to 

 give a reason for the various forms employed, and explain 

 the influence of this horn or that loop superadded to the 

 simple line in modifying the sound. We are, however, at a 

 loss to discover what possible connection of affinity or 

 even of analogy can exist between the signs O and O and 

 the scunds they represent. Whatever the recondite re- 

 searches of the antiquarian may discover, the letters of 

 the alphabet arc practically recognised and universally 

 received as arbitrary signs for particular sounds. The 

 mastery of the alphabet is only the recognition and remam- 

 brancc of the different signs and the sounds they repre- 

 sent. 



This mnemonic education is not unfrequently the only 

 cducat'oi which some attain to, or perhaps arc capable of. 

 In science not a few are looked up to as masters whose 

 extensive knowledge is nothing more than the faculty of 

 discerning differences joined to a good memory. The 

 raticna'e of the difference is another matter; perhaps 

 they are mentally incapable of appreciating whether the 

 distinguishing characteristics at once perceived by them 

 are dependent on the absence of affinites or of analogies. 

 The differences exist — that is their goal. 



Miny entomologists prosecute their labours on this low 

 platform, and in botany the mere herbarium systematist 

 occupies the same position. The one classes beetles, and 

 the other plants as the lexicographer arranges words, by a 

 method that exhibits their differences and permits easy 

 reference. 



But in no division of science is this class so common as 

 in giology. The mere perception and memory of differ- 

 ences will give one a high class position as a palcuon- 

 tologist : and much useful work will such a one do — work 

 necessary to the progress of science. True, it is not the 

 highest class of work, and too frequently men who are ex- 

 perts at it aim at something higher. But deficient in the 

 power of appreciating analogies, or recognising affinities 

 in the points of resemblance, or their absence in the points 

 of differer.ee ; deficient also in the exact knowledge of 

 zoology or botany, such men have grandiloquently pro- 

 claimed and ignorantly and of course obstinately defended 

 the most absurd opinions. Confined to the useful work of 

 separating and recording different forms their services to 

 science ai'O most valuable, but the interpretation of obscure 

 structures, and the higher problems of science, must be 

 left to others able to deal with them. 



No greater source of the evils we deprecate exists than 

 the common but erroneous practice of separating pakeon- 



VOL. VI. 



tology as a science by itself. Palaeontology has no grounds 

 for recognition as an independent science. The organisms 

 of an existing geographical province might be excluded 

 froTi zoology and botany on the same grounds that are 

 employed to exclude the plants and animals of a geological 

 period. Zoologists are far ahead of botanists in getting 

 ri J of this error. Extinct forms have their place in every 

 philosophic estimate of the animal kingdom. In botany, 

 on the other hand, the study of fossil forms has been re- 

 cently characterised as a non-scientific pursuit engaging 

 the attention of the "geologist"; extinct plants are ex- 

 cluded from systematic works, and if dealt with at a'l in 

 class books, all reference to them is eliminated from the 

 general text, and they are confined to a page or two, or 

 relegated to an obscure appendix. 



Great praise is due to Prof. Balfour for introducing a 

 different order of things. His manuals have always to a 

 greater extent than any others published in the English 

 language dealt with fo5sil plants ; and he has now given us 

 a special introduction to botanical pateontology. Fiom 

 the position obtained by the study of structural and 

 systematic botany he deals with the problems presented 

 by fossil plants 



The earlier pages of the work are occupied with pre- 

 liminary considerations as to the difficulties which present 

 themselves in attempting to determine fossil plants, the 

 different conditions of preservation in which their remains 

 occur in the stratified rocks, the accepted classification of 

 the sedimentary deposis, and the like. 



The plan of the work itself is to treat of the plants as 

 they are associated in the different recognised formations. 

 Looking at pa'ajontology as a separate section of the 

 science of botany this is no doubt the obvious method of 

 treatment, just as in geographical botany we deal with the 

 different provinces of the surface of the earth and th ; 

 floras which characterise them. If, however, the strati- 

 graphical aspects had been subordinated to the systematic, 

 a more valuable and instructive exhibition of the pist 

 vegetation of the globi would have baen before us. For 

 example, had the Coniferac been traced from the first 

 known occurrence of Abletineous wood in the Devonians, 

 through the anomalous Araucirian wood and theTaxineous 

 fruits of the Carboniferous rocks, the last types represented 

 by the Walchias of the Permians and the Voltzias of the 

 Trias, up to the appearance of the still existing group; in 

 the Oolitic and Cretaceous rocks, an exhibition of extinct 

 forms would have been given v/hich would have conveyed 

 to the botanist a clear and comprehensive view of the 

 Order. In this way important light would be thrown on 

 the present geographical distribution of orders and even 

 genera. Look, for instance, at Araucayia and Sequoia, — 

 two genera limited in numbers as well as in geographical 

 distribution. We find the first represented by sevei-al 

 species in our Secondary rocks, entirely absent from the 

 Teitiaries, and at length banished to the southern hemi- 

 sphere ; while Sequoia appears in the Cretaceous strata, 

 persists through the lower Tertiaries, and is now limited 

 to a small geographical province in Western North 

 America. 



Nevertheless much may be said for the method adopted 

 by Prof. Balfour. So long ago as the year 1828, Adolphe 

 Brongniart detected a correspondence between the great 

 divisions of the vegetable kingdom and the great epochs 



