MALPIGHI, SWAMMEBDAM, LEEUWENHOEK. 583 



and its form after contraction in the 'tayle which retains those 

 windings and turnings.' 



He discovered also the Botifers, those favorites of the amateur mi- 

 croscopists, made so familiar to the general puhlic in works like Gross's 

 'Evenings at the Microscope.' He showed their remarkable powers of 

 resuscitation after complete drying. He observed that when water con- 

 taining these animalcules evaporated they were reduced to fine dust, but 

 became alive again after great lapses of time by the introduction of 

 water. 



He made many observations on the microscopic structure of plants. 

 Fig. 9 gives a fair sample of the extent to which he observed the 

 cellular construction of vegetables and anticipated the cell-theory. 



.... 





ft? 



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11 



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Fig. 9. From Leei'wkxhoek's 'Arcana Nature.' 



While Malpighi's work in that field was more extensive, these sketches 

 from Leeuwenhoek represent very well the character of the work of 

 the period on minute structure of plants. 



It remains to say that on the two biological questions of the day 

 he took a decided stand. He was a believer in preformation or pre- 

 delineation of the embryo in an extreme degree, seeing in fancy the 

 complete outline of both maternal and paternal individuals in the 

 spermatozoa, and going so far as to make sketches of the same. But 

 upon the question of the spontaneous origin of life he took the side 

 that has been so triumphantly demonstrated in this century against 

 the occurrence of spontaneous generation. 



We see in these three gifted contemporaries different personal char- 

 acteristics. Leeuwenhoek, the composed and strong, attaining an age 



