i56 HISTORY OF PHYSIOLOGY. 



left to his successors. Without dwelling on the intermediate labors, 

 we come to modern times, and find that this examination owes its 

 greatest advance to those who had the greatest share in the discovery 

 of the circulation of the blood : Fabricius of Acquapendente, and Har- 

 vey. The former 3 published a valuable work on the Egg and the 

 Chick. In this are given, for the first time, figures representing the 

 developement of the chick, from its almost imperceptible beginning, to 

 the moment when it breaks the shell. Harvey pursued the researches 

 of his teacher. Charles 4 the First had supplied him with the means 

 of making the experiments which his purpose required, by sacrificing 

 a great number of the deer in Windsor Park in the state of gestation : 

 but his principal researches were those respecting the egg, in which he 

 followed out the views of Fabricius. In the troubles which succeeded 

 the death of the unfortunate Charles the house of Harvey was pillaged ; 

 and he lost the whole of the labors he had bestowed on the generation 

 of insects. His work, Exercitationes de Generations Animalium, was 

 published at London in 1651 ; it is more detailed and perfect than 

 that of Fabricius ; but the author was prevented by the unsettled condi- 

 tion of the country from getting figures engraved to accompany his 

 descriptions. 



Many succeeding anatomists pursued the examination of the series 

 of changes in generation, and of the organs which are concerned in 

 them, especially Malpighi, who employed the microscope in this inves- 

 tigation, and whose work on the Chick was published in 1673. It is 

 impossible to give here any general view of the result of these laborious 

 series of researches : but we may observe, that they led to an extremely 

 minute and exact survey of all the parts of the fetus, its envelopes and 

 appendages, and, of course, to a designation of these by appropriate 

 names. These names afterwards served to mark the attempts which 

 were made to carry the analogy of animal generation into the vegeta- 

 ble kingdom. 



There is one generalization of Harvey which deserves notice. 5 He 

 was led by his researches to the conclusion, that all living things may 

 be properly said to come from eggs : " Omne vivum ex ovo." Thus 

 not only do oviparous animals produce by means of eggs, but in those 

 which are viviparous, the process of generation begins with the deve- 

 lopement of a small vesicle, which comes from the ovary, and' which 

 exists before the embryo : and thus viviparous or suckling-beasts, not- 



Cuv. Hist. Sc. Nat. p. 46. 4 Ib. p. 53. 6 Exerc. Ixiii. 



