60 Cooperative Investlgatioiis on Flants 



the same plant, these may bc tcruiod siblings or half-sibliiigs, and may be classified 

 by compounding the above terms, thus instead of speaking of a homotropic- 

 homotropic pair we can without confusion speak siniply of a homotropic pair, and 

 instead of an exotropic-homotropic or exotropic-endotropic pair, simply of an 

 exhomotropic or an exendotropic pair. Further an interesting series of subcases 

 arises when there is a miitual interehange of poilen betwcen two flowers or piants. 

 If the interehange be such that the ovary of onc flower (<;) receives poilen from the 

 anther of a flower on the same or on a second plant {A' or B), wliile the ovary of 

 this latter flower (r;' or h) receives poilen from the anthers {A) associated with the 

 first ovary, we shall speak of this relation as hypermeüitropic. If the firet ovary 

 (a) receives from an anther (^-i' or B) associated with the second ovary {a or b), 

 but the second ovary from the anthers of the first plant not associated with the 

 first ovary (-4"), then the relationship is mesomeUttropic. Final!}- if the interehange 

 be between two piants the poUeu of one going to the other, but not the poilen 

 from anthers associated with the ovaries fertilised, then the relationship is 

 p-ometatropic. If the interehange is only half completed, then we have the three 

 corresponding typcs of hemimetatropy . 



We are now able to classify the various forma in plauls corresponding to the 

 fraternal relationship. 



Füll and Half-Sibship in Piants. 



Tcrminolot;y Symbol 



I. Co-ovarial syuanthic homotropy aA . aA 



„ dianthic endhomotropy aA . aA' 



„ synanthic endotropy aA' . aA' 



„ dianthic endotropy aA' . aA" 



„ dysanthic exhomotropy aA . aB 



„ dysanthic exendotropy aA' . aß 



„ synanthic exotropy aB . aB 



„ dianthic exotropy aB . aB' 



„ dysanthic exotropy aB.aG 



II. Bi-ovarial dianthic homotropy aA.a'A' 



„ synanthic endhomotropy aA . a'A 



„ dianthic endlioniotropy 0.4 . a'A" 



„ dysanthic exhomotropy aA . a'B 



„ dianthic hypernietatropy aA'.a'A 



„ dianthic hemi-hypermetatropy aA'.a'A" 



„ dysanthic hemi-hypermetatropy aA' . a'B 



„ synanthic endotropy aA" . a'A" 



„ dianthic endotropy aA" . a'A'" 



„ dysanthic exendotropy aA".a'B 



„ synanthic exotropy aB . a'B 



„ dianthic exotropy aB.a'B' 



„ dysanthic exotropy aB . a'C 



