THE PRINCIPLE 



HOMOEOSIS IN PLANTS 



CONTRIBUTIONS FROM THE AMES BOTANICAL LABORATORY, NO. 9 



Robert Greenleaf Leavi 



(WITH NINETEEN FIGURES) 



TT 



When viewed in their relations to morphogenetic and broader 

 evolutional problems (as distinguished from narrower phylogenetic, 

 or genealogic, problems) numerous facts of teratology-a descriptive 

 cult without unifying principles, heretofore pursued chiefly by the 

 vaguely curious and lending itself discreditably with equal readiness 

 to either side of many a morphological discussion in the past-mani- 



test a snenal ar»H K;*»k ™i..~ r™ r 



fest a special and high value. 



m _ 



, ■ °" — <•«• *"c proauction ot form from form- 



essness m the egg-derived individual, the multiplication of parts and 



,l OT ^. Creatl ° n ° f diversit y am °ng "tern, is an actual evolu- 



actual evolu- 



ri™ ^ u- i. J " XXXKJll & "icin, is an actual evoiu- 



has diiiI, 1C H r y ° ne may aSCCTtain the facts > but ° f whi * no one 

 evolu LTf myS ' ery " ^ Significant measur - This micro- 



lies a 1 r S T mtegral Palt ° f the ^ nd e ™ luti °° P^lem and 



:« L h f r,: f :!: s .° ! hat _T! shau h - - -^^ t he „**» 



Morph 



more 



work Tfc* a i lllcn me evolutionists must 



"be Ich t PmeDt ' ° r mOT P h °<^is, of a single individual- 



h omo^neti CaSe " ^ imPr ° Ve ° Ur insi g ht in 'o the nature of 



greater" IT "^"^ «>*d-may be of as 



LfXlJ:tZT, I"* "**"* as •* -W of a new 



^isasstxrt than the **' prob - 



upon abnormalities i„ I Z '° ?7 0ut Certain observations 



the bearing which some „f ,h T , ^ make clear ' als0 ' 

 upon types of raci "1° , - °T^ ind ™ d » al ™ iati <- ha ™ 



normal 



In this connection 



some 



descry 



one, i „ any complete account rf the evohX* f ' 

 Botanic! Ga M tte, vol. 47l evolution of species. 



main 

 minor 



[3 



