OUR EMBRYONIC DEVELOPMENT. 55 



minute and transparent that it could not be detected ; 

 that, therefore, the whole development was nothing 

 more than a growth, or an " unfolding," of the parts 

 that were already "in-folded" (involuta). This 

 erroneous notion, almost universally accepted until the 

 beginning of the present century, is called the "pre- 

 formation theory"; sometimes it is called the "evo- 

 lution theory" (in the literal sense of "unfolding"); 

 but the latter title is accepted by modern scientists for 

 the very different theory of " transformation." 



Closely connected with the preformation theory, 

 and as a logical consequence of it, there arose in the 

 last century a further theory which keenly interested 

 all thoughtful biologists — the curious " theory of scatu- 

 lation." 1 As it was thought that the outline of the 

 entire organism, with all its parts, was present in the 

 egg, the ovary of the embryo had to be supposed to 

 contain the ova of the following generation ; these, 

 again, the ova of the next, and so on in infinitum! 

 On that basis the distinguished physiologist Haller 

 calculated that God had created together, 6,000 years 

 ago — on the sixth day of his creatorial labours — the 

 germs of 200,000,000,000 men, and ingeniously packed 

 them all in the ovary of our venerable mother 

 Eve. Even the gifted philosopher Leibnitz fully 

 accepted this conclusion, and embodied it in his 

 monadist theory ; and as, on his theory, soul and 

 body are in eternal, inseparable companionship, the 

 consequence had to be accepted for the soul; "the 

 souls of men have existed in organized bodies in their 

 ancestors from Adam downwards — that is, from the 

 very beginning of things." 



1 Literally "boxing-up" or "packing"; the force of the term 

 appears in the next sentence. 



