Morphologie, Teratologie, Befruchtung, Cytologie. 501 



cees. Hooker et Thomson ont decouvert une Crassulacee ä fleurs 

 anisomeres et Tont decrite comme gcnre nouveau, Tviactinia. 

 L'auteur donne une description nouvelle et detaillee de l'espece 

 unique, T. vevticülata. Cette espece se rapproche beaucoup du 5^- 

 dimi bracteation , mais s'en eloigne par ses fleurs anisomeres. Pour- 

 tant, le T. vevticülata n'est pas la seule Crassulacee qui possede des 

 fleurs anisomeres. L'auteur a trouve l'anisomerie florale aussi chez 

 le S. tricarpimi et chez une espece qui n'a point encore €.\.t decrite, 

 originaire du Su-tchuen. La nouvelle espece est fort eloignöe du 

 Tnactinia, dont eile ne se rapproche que par ses fleurs anisomeres. 

 Par contre, eile est tres voisine du 5. filipes Hemsley, dont eile se 

 distingue cependant par son anisomerie florale. Mais eloigner cette 

 plante du S. filipes pour la rapprocher du Tviactinia violerait aussi 

 manifestement les aflinites naturelles que la Separation generique 

 du Tviactinia et du 5. bvacteatinn. 



En realite, l'anisomerie florale est une anomalie que Ton ren- 

 contre dans plusieurs Crassulacees fort distinctes. Sur un tel carac- 

 tere, ii est donc impossible de baser une Classification naturelle. 

 C'est pourquoi le genre Tviactinia doit etre supprime. Le T. verti- 

 cillata deviendra donc le 5. vevticillatum Hamet, nomen novum. 

 Quant ä la plante du Su-tchuen, eile devra etre rangee dans le 

 genre Sediini dont eile constituera une espece nouvelle, S. Bonnievi 

 Hamet, spec. nov. Jongmans. 



Harris, J. A., On the relationship between the number 

 of ovules formed and the number ofseeds developing 

 in Cevcis. (Bull, torrey Botan. Club. XLI. p. 243-256. 3 Fig. 1914.) 



The following summary and discussion are published at the 

 end of the paper. 



The paper embodies the results of an attempt to ascertain the 

 relationship between the number of ovules per pod and the capacity 

 of the pod for maturing its ovules into seeds in the leguminous 

 plant Cercis canadensis. 



The correlations for number of ovules formed and number of 

 seeds developing per pod, roz, have always been found positive and 

 of a moderate, considerable or even high intensity. 



Regression of number of seeds on number of ovules per pod 

 is sensibly linear in a population of pods from many individual 

 trees. Possibl}', however, there is a departure from linearity in the 

 pods with eight ovules; in the largest series there are only 36 ol 

 these pods out of a total of 28, 554, and this number is too small 

 to be given great importance. 



The significance of the linearity of regression is two-fold. 

 StatistJcally, it justifies describing the interdependence between the 

 number of ovules formed and the number of seeds maturing by 

 the coefficient of correlation. Biologically, it shows that the rate of 

 increase in number of seeds developing per pod remains the same 

 as we pass from pods with the lowest to pods with the highest 

 numbers of ovules. 



Wherever large series of pod have been examined, the correlation 

 between the number of ovules per pod and the capacity of the pods 

 for maturing their seeds, roz. has a negative sign and a low, 

 usually a very low, magnitude. For every large series examined 

 the value of roz has been over 2.5 times its probable error. These 

 evidences can leave little doubt of the exislence of a slight negative 

 relationship between the number of ovules formed and the capacity 



