The germ-cells, 617 



is at all an unimportant one, but that it really postulates a fair know- 

 ledge of the mode of development of the organism as a whole. 



The history of embryological doctrine of the 19th century, written 

 at the close of the new century, now about to dawn ^), will doubtless 

 be a curious document. Though it will vastly exceed in size that of 

 the 18th, and embrace far more real discoveries, like the latter its 

 story is bound to include some remarkably erroneous doctrines. Nor 

 will these be confined to its earlier years ! 



The controversies of the ovists and animalculists amuse us now, 

 though we still cling to an allied line of thought. Perhaps the quotation 

 from VON Baer given above may not have told its own story with 

 the bluntness, appertaining to it. In reality it refers to the contro- 

 versies, which raged around the doctrines of Copernicus, those of 

 Harvey on the circulation of the blood, and Peysonel's statements 

 of the animal nature of the corals. These are instances, as such cited 

 by VON Baer, of discoveries and ultimate triumphs, leading to the 

 overthrow of anthropocentric superstitions. Along with countless other 

 cases they illustrate how every new advance, great or small, is strenu- 

 ously opposed, its author anathematized or ridiculed, unless it happen 

 to dove-tail into existing doctrines. 



The anthropocentric theory of the universe has long been banished 

 from certain domains of human knowledge. Thanks to the recapitul- 

 ation-theory, as well as to certain other factors in the- early history 

 of the science, it still dominates comparative embryology. 



Man and his history form the central points of the science. We have 

 even carried over our social conceptions of the parentage of the child 

 into embryology. It is believed, that the tissues of the father produce 

 the male germ-cells or spermatozoa, those of the mother the female 

 ones or eggs. 



In all this we have forgotten to reckon with Nature. Under 

 parentage we understand the actual origin not only of the organism, 

 but also of the two cells, which form it. Nature, however, carries 

 back the origin of the germ-cells so far into the remote past, that 

 our tracing of pedigrees, no matter of what sort, or how noble, how 

 long, seems but a nonsensical trifling, a childish play. 



And the wonder and mystery of it all ! von Baer, who possessed 

 a far deeper insight into embryological problems, even in his old age, 



1) _ Written in Dec. 1900. 



