Old Sutural History Books. 
“ Ovum esse primordium commune omnibus Animalibus ” 
(subsequently expressed by the aphorism “ Omne Vivum ex 
Ovo ”), that was announced in his Exercitationes de Generatione No. 36. 
Animaltum (London^ 1651). 
Secondly the discovery of the Lymphatic System by 
Gaspard Aselli [c. 1581-1626] and Olaus Rudbeck [1630- 
1702]. 
THESE discoveries were followed by the investigations of the 
intimate structures of Animals and Plants made by a group of 
eminent contemporary naturalists, with the aid of the then 
new instrument, the Microscope. 
Robert Hooke [1635-1703], the versatile Curator of 
Experiments to the Royal Society, in 1665, published his 
Micrograph'ia^ a work in which the author intentionally touched No. 40. 
upon many interesting subjects without working any of them out, 
content if he furnished the groundwork for others to build on. 
Among his observations were some of great import. Thus 
he first saw and named the “cells” in plants, for his subject 
being a dried cork he naturally judged them empty. 
Hooke also studied the minute quartz crystals which he 
found in the cavity of a flint. Their mode of reflecting and 
refracting light, with the regularity of their figures, led him 
to suggest that crystals are built up of spheroids. 
To Geology, also, Hooke was an important contributor. 
Supporting the organic origin of fossils, he explained in his 
Lectures and Discourses of Earthquakes (Posthumous JVorks^ 
the processes of petrifaction, inclined towards the extinction of 
species in some cases and substituted a diluvial theory of His own 
to account for them, in lieu of the Noachian Deluge. 
Jan Swammerdam [1637-1680], a noted Dutch physician 
and naturalist, specially devoted himself to the study of the 
anatomy of Insects. His Historia Insectorum generalis was 
published in 1669. 
Nehemiah Grew [1628-1694], Secretary to the Royal 
Society, made a number of most careful researches into the 
Anatomy of Plants that were laid before the Royal Society 
in a series of papers between the years 1671 and 1677. 
Among other things he correctly surmised the true nature 
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