HOOKE'S MICEOGRAPHIA 



PROFESSOR LORAXDE LOSS WOODRUFF 



Biological research in general during the latter part 

 of the seventeenth century begins to be permeated with 

 an attention to details and with an intensive critical 

 analysis which is conspicuous by its absence in practic- 

 ally all but the masterpieces of previous times. Nor is 

 the explanation far to seek. The improvement of simple 

 lenses and the invention of the compound microscope 

 provided a method of increasing the apparent size of 

 things which, in addition to revealing a new world of 

 animalcules " beyond the range of unaided vision, 

 brought to the attention of students finer details of struc- 

 ture of the higher animals and plants. But, as Sachs 

 has emphasized, the use of magnifying glasses contrib- 

 uted an advantage of still another kind— it taught those 

 who employed them to see scientifically and exactly. In 

 equipping the eye with increased powers the attention was 

 concentrated on definite points and observation had to 

 be accompanied by conscious critical reflection in order 

 to make the object, which is observed in part only by the 

 microscope, clear to the mental eye in all the relations of 

 the parts to each other and to the whole. Therefore, in 

 marked contrast with the very slow progress in obtaining 

 a mental mastery over the macroscopic morphological 

 features of plants and animals is the work of the early 

 students with the microscope such as Hooke and Grew in 

 England, Malpighi in Italy, and Swammerdam and 

 Leeuwenhoek in Holland. 



The earliest clear appreciation of the importance of 

 studying nature with instruments which increase the 

 powers of the senses in general and the vision in ])ar- 

 ticular, is found in a remarkable book by a remarkable 

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