unaccomplished to accomplished. By his investigations 

 "Swammerdam showed that insects, by their respiratory 

 organs, are similar to plants, and that in nature, an 

 order of gradualness, descending from animals to plants, 

 exists. However, there may be, in addition, intermediate 

 substances between these and others" (Letter of Leibnitz 

 to Bung). And in another letter: "I am sure, that these 

 substances must be present, and natural science may dis- 

 cover them. Nature never disturbs continuity anywhere. 

 It does not make leaps. All categories of substances of 

 nature form one sole chain, where different classes, like 

 links, so closely join to each other that for sensual 

 presentation it is impossible to determine the point, where 

 each of them begins or ends" (cited by Kuno Fisher) 

 ("History of new philosophy, V. Lebnitz", p. 460) (38) . 



(16) About this change of his opinions, Haller wrote 

 the following: "In the body of animal, there is no part 

 which can originate earlier than the other: all of them 

 are formed at the same time... If Harvey supposed that 



he discovered the epigenetical development, it is because 

 from the beginning he only saw small haziness and then the 

 rudiments of the head and eyes, exceeding in size all other 

 bodies, and finally gradually — the internal organs. More 

 than 20 years ago, i.e. before my numerous observations on 

 eggs and females of Tetrapoda, I used this argument to prove 

 that embryo strongly differed from the formed animal, while 

 I confirmed, that in animals at the moment of conception 

 parts which were present in completely formed animal were 

 absent. From this time, I had the complete possibility to 

 confirm that all that was deduced by me against preformation 

 theory, in fact speaks in its favor" (cited by Dzh. Needham, 

 History of Embryology, p. 226-227) (39). 



(17) On the basis of the confirmation of the Bible, 

 that earth and mankind populating it, have existed about 

 6000 years and from that the average duration of life of 



man is equal to 30 years, Haller calculated, that God created 

 at the same time a minimum of 2000,000,000,000 people (cited 

 by article of Kirchhoff on Wolff, p. 204) (39) . 



(18) Speaking about the impression produced on contem- 

 poraries by the discovery of Bfennet (about the development of 



607 



