Tlic Biociuuniic lujiiafiiHi. . (>o3 



changed, arc usually dcsignalcd, amongst paleontologisis, 

 as mutations.' The name \arictics is ai)|)lic(l bv tlicm t<> 

 those lorms which li\e side by side at the same lime and 

 constitute tlie rays of a fan or the units of a swarm in 

 our diagram in h'ig. 149. In this sense my Ooiotlicras 

 are related to one another as varieties, hut to the parent 

 form as mutations. In experimental science, however, 

 these |)aleontological terms would prove very incon- 

 venient: and the older meaning of the word "mutation." 

 as it was used by botanists long before Waagkn. is 

 greatly to be preferred. W^hat varieties are. will f«jr a 

 long time remain a topic of discussion.^ 



§ T4. THE BTOCTTROXTC EQLWTION. 



The characters of organisms are not unlimited in 

 number. However complex the structure of a higher 

 plant or animal may seem, and how^ever much the char- 

 acters which compose them may give the impression of 

 being unlimited, no one will deny that, when more closely 

 examined, their organization will appear, although not 

 simple, at least a great deal simpler than it seemed to l)e 

 at first sight. 



Cope states that for the 28,000 species of vertebrates 

 there are only a few^ hundred organs on which their \aria- 

 tion and diversity rests. ^ If we examine the dichotomou>^ 

 tables for the identification of species in the most variou*^ 

 groups of animals and plants, we are astounded at the 



^ See H. K. Ziegler. Uchcr den drrccififioi Shmd drr Drsi'mdi'iic- 

 Ichre ill dcr Zooloi^ir. Jena, 1Q02: and tlie same in Zool. Cciitralblatt, 

 1902, Nos. 14-15. 



"See above § .^. p. ^jS. .^acerkt flefincfl mntations a>; "I'an'i'ti's 

 qui sc fonncnt sous nos ycux." Ann. Sc. nat., 1826. p. 299 



' T. I). Cope, The Priinary luulors of Organic F.voUttion. 1806. 



