688 JOHN BEARD, 



name, and in developmental researches they have looked only at one 

 aspect of the question, the formation of an embryo. It is, perhaps, 

 to the recapitulation-theory of Kielmeyer and Oken that the blame 

 of this should be laid. 



The formation of an embryo is a mere incident in a 

 certain chain of phenomena! 



The main purpose of these is the development of a new set of 

 germ-cells. 



In nature, in j&ne, the formation of a set of germ- cells is of in- 

 finitely greater importance than the development of an embryo. 



Confessedly, our schemes and nomenclatures are all conveniences 

 of our own, about which Nature never concerns herself in the least 

 — "Die Natur geht ihren Gang, und was uns als Ausnahme erscheint, 

 ist in der Regel" (Goethe). 



The kind of animal life, on which most of her fostering care is 

 bestowed, is that of the unicellular organisms. As Weismann has 

 shown, these from their nature are practically endowed with immort- 

 ality. To a recognition of this attribute may be ascribed the circum- 

 stance, that she made them the basis of what we term Metazoa and 

 of the life-histories of the latter. 



At the bottom all animal life is made up of unicellular organisms. 

 At the sacrifice of their Protozoan characters to some of these is 

 given the formation of what we term a Metazoon. This is really a 

 sterilised person, which by the sacrifice of its unicellular attributes 

 has landed itself in a cul-de-sac by blossoming-forth into a so-called 

 "sexual person" or Metazoon. Its life is limited, for it has got out 

 of the eternal round, making up the cycle of life of a unicellular 

 organism. 



Whereas the life of the latter may be represented by a circle, 

 on which at a certain point, the conjugation, there starts a new circle, 

 the life of a Metazoon is a straight line of limited length. The germ- 

 cells, on the other hand, by retaining their unicellular characters 

 from generation to generation, steer clear of the cul-de-sac of em- 

 bryonic formation. As long as they can go on like the Protozoa in- 

 creasing by fission, and, finally, after a new conjugation passing a 

 portion of the new cycle in an embryo, formed by the self-sacrifice of 

 one of their number for the good of the rest, so long their tenure of 

 life is secured. 



In witness of the truth of this how many Metazoa are there not, 

 whose individual lives are drawn out but long enough for the neces- 



