NATURE 



261 



THURSDAY, FEBRUARY 4, 1875 



BOTANICAL PROBLEMS* 



SUCH is the title of an article by Prof. Cohn on the 

 history of botany in the new German periodical, the 

 Deutsche' Rundschau. 



Circumstances seem to have determined the direction 

 of the researches of English botanists of the present 

 period, who, almost without exception, have devoted their 

 whole time to descriptive botany. On the other hand, 

 continental botanists have pursued vegetable physiology 

 and anatomy with great assiduity. This separation of 

 what should be inseparable branches of the same science 

 is in all probability only temporary. The great demand 

 for descriptive works on the vegetation of our various 

 colonies, and the immense mass of undescribed plants in 

 our herbaria, have, doubtless, influenced in no small 

 degree the direction of the labours of our botanists. In 

 return, poverty in herbarium specimens and books renders 

 it impossible for many continental botanists to pursue 

 successfully systematic botany. Apart from its import- 

 ance from an economic point of view, descriptive botany 

 is of relatively little absolute value, and must be ex- 

 tremely unsatisfactory to minds labouring to prove the 

 immutability of species on the one hand, or their varia- 

 bility within certain defined Umits on the other. Whether 

 we follow Jordan, with his 200 species of Draba (Ero- 

 phila), the result of the dismemberment of D. vernd ; or 

 Regel, who combines Vitis vinifei'a, Lahnisca, vulpiiia, 

 &c., we should equally drift into an utterly impracticable 

 and useless system, and one of no utility whatsoever in 

 the solution of problems which we may reasonably hope 

 to unravel. 



This brings us to a consideration of Cohn's article, pro- 

 fessedly written to show the importance and popularise 

 the study of botany, more particularly in its biological 

 bearings. Naturally we may look for some tolerably 

 sharp criticisms of systematic botany studied alone, and 

 the writer is to some extent justified in more especially 

 singling out England. Nevertheless, we think that its 

 importance is underrated by some continental botanists. 

 Prof. Cohn is a great admirer of the Aristotelian school, 

 and to the great master and his pupil, Theophrastus, he 

 gives the credit of having initiated the scientific study of 

 plants, which after their time declined and lay dormant 

 for upwards of 2,000 years. The discoveries of the last 

 two centuries he consequently looks upon as a revival of 

 this science, and as so many solutions of problems pro- 

 pounded, though, as he admits, not answered, by Theo- 

 phrastus. We certainly should assign a more modest 

 share of credit to these early philosophers, and Cohn's 

 quotation from Goethe, " when we consider the problems 

 of Aristotle we are astonished at the great powers of 

 observation and universal perception of the Greeks ; but 

 they are too hasty, passing at one step from the pheno- 

 mena to their interpretation, hence their conclusions are 

 often inadequate and theoretical," does not strengthen his 

 position. After all, this is a question of little moment. 

 It is quite true that nothing approaching a philosophical 



Heft i). 



' Botanische Proble 



Prof. Cohn [Denliche Rundschau, 



Study of plants was resumed before the seventeenth 

 century. 



Prof. Cohn gives a sketch of the history of botany, 

 hastily disposing of the " root-grubbers and collectors of 

 simples," from Dioscorides and Galen down to the 

 herbalists of the seventeenth century. To Erasmus he 

 traces the impulse given to this and other branches of 

 learning in the Netherlands and North-western Germany. 

 The fact that the dwellers on the Rhine did not find the 

 same plants described by Dioscorides, may be said to 

 have offered the first lesson in phytogeography, which 

 was rapidly developed by the spirit of travel and dis- 

 covery which soon set in. 



Naturally one of the first things to impress itself on the 

 minds of those engaged in the study of plants as their 

 numbers increased, was the necessity for some system of 

 classification and nomenclature. The history of bino- 

 minal nomenclature and the sexual system of Linnteus, 

 and the natural system of A. L. de Jussieu, are too well 

 known to need repetition, and Cohn does not attempt 'o 

 trace the gradual growth of knowledge which led up to 

 the development of these ideas. In fact, he appears to 

 attach so little importance to systematic botany, that he 

 goes on to say : " Under the dominating influence of 

 Linnajus, botany seems to have stagnated more and more, 

 whilst a new spirit had been infused into the study of 

 other sciences." He then refers to the philosophical 

 teachings of Bacon, which fell upon a well-prepared soil 

 and eventually bore fruit. Botanists began to make 

 experiments and study the laws of nature. Hales was 

 the first to investigate some of the phenomena of plant 

 life in their physical aspects. Du Hamel, Bonnet, Ingen- 

 housz, Priestley, Saussure, and others followed, and raised 

 the study of vegetable physiology and chemistry to a 

 level with the exact sciences. The solution of other 

 botanical problems is given in outline, and where only a 

 few names could be given it is not to be wondered at that 

 Germans figure more prominently than would be the case 

 in a detailed history. The merit of solving a particular 

 botanical problem can in few instances be claimed for 

 one man alone. Discovery is progressive, and a com- 

 plete insight into many of the processes of plant-life have 

 been gradually unfolded. Goethe's solution of the mor- 

 phological problem is naturally dwelt upon at some 

 length, and no one will gainsay its importance in syste- 

 matic botany. Grew and Malpighi initiated vegetable 

 anatomy, and it is a noteworthy fact, says Cohn, that the 

 papers of these two fathers v^ere handed over to the 

 Royal Society of London on the same day, Dec. 29, 1671. 

 But a hundred years elapsed before their labours were 

 appreciated and continued. 



In the revival of this branch of botany Prof Cohn has 

 a strong array of German names, many of them of world- 

 wide fame. The conceptions of Darwin and their impo. - 

 tance are barely mentioned, though in no country have 

 they exerted a more fundamental influence than in 

 Germany. Passing into the region of unsolved problems, 

 Cohn cites the unconquerable vitahty of the potato fungus, 

 and the uncertainty existing respecting the presence and 

 signification of minute fungi in cholera and other 

 diseases. 



In conclusion, Prof. Cohn rejoices in the fact that 

 botany has freed itself from the fetters which formerly 



Vol, XI.— No. 275 



