230 



SCIENTIFIC THOUGHT. 



and botany tell us, the use of the microscope had 

 made little or no progress ^ during the eighteenth 

 century : the study of structures and tissues had lost 

 interest in comparison with the study of the physi- 

 ological functions of the parts of plants and the organs 

 of animals, which had been respectively furthered by 

 2R. Hales in England and by Haller in Germany." Our 



Its improve- 

 ment, century thus found the morphological studies of the 



imperceptibly small in a very backward state : it had 

 to improve the instrument for its research pari passu 

 with this research itself.^ But it has been truly re- 

 marked that the increased use of the microscope 

 necessitated likewise a mental training in the inter- 

 pretations and delineations of what was observed 

 through it. " By fortifying the eye with the micro- 



^ "So long as, in consequence of 

 the imperfections of optical instru- 

 ments, deceptive images existed, 

 and, for instance, all microscopical 

 structures appeared as composed of 

 rows of beads, the explanation of 

 what was seen stood under the in- 

 fluence of deceptions, which were 

 only gradually recognised as such " 

 (Carus, 'Gesch. d. Zool.,' p. 629). 

 Compare also what Sachs says 

 (Gesch. d. Bot.,' p. 241). 



^ " The characteristic feature of 

 that period laj- in this, that the 

 examination of the finer structure 

 is always mixed up with reflections 

 on the functions of elementary 

 organs, so that anatomy and phy- 

 siology always support each other, 

 but also, in consequence of their 

 imperfect state, do each other in- 

 jury " (Sachs, loc. cit., p. 240). 

 Similarly Carus {loc. cit., p. 567), 

 " Through the progress which phy- 

 siology made, thanks to Haller's 

 activity, zootomical investigations 



took a direction which brought 

 them into complete dependence on 

 physiology, . . . and retarded the 

 progress of zoology by diverting at- 

 tention from its primary object — 

 the exposition of animal forms and 

 their differences." 



' As late as 1827 Aug. Pyrame 

 de Candolle could still write ('Or- 

 ganographie v^gdtale,' vol. i. p. 7), 

 " De nos jours, MM. Mirbel, Link, 

 Treviranus, Spreugel, Rudolphi, 

 Kieser, Dutrochet, et Amici out 

 public des recherches tres d^licates 

 sur le tissu vegdtal, et les ont ac- 

 compagnees de figures nombreuses 

 et soignees ; mais la necessite d'em- 

 ployer continuellement dans ces 

 recherches un instrument aussi 

 difiBcile h, bien manier que Test le 

 microscope compose, fait que malgr^ 

 I'habilet^ de ces observateurs, I'anat- 

 omie delicate des veg^taux est encore 

 . . . d'une incertitude desesperante 

 pour les amis de la v^ritd. " 



