EXTR4.CIS AND ABSTRACTS. 313 



to believe that the higher groups can be totally devoid of a sexual 

 apparatus. 



Use of the hjgromfitric twisting of the tails of the carpels of 

 Erodium. — Prof. Gray gives (Amer. Journ. So. and Arts, Feb., 

 1876) a short account of the function of the long twisted style of 

 Erodium and the awn of Stipa. He comes to the same conclusion as 

 Eoux, and more recently Mr. F. Darwin, viz., that the twisted 

 portion by its movements buries the carpel in the earth. Eoux has 

 observed that when the carpel of Erodium has thus been planted, the 

 beak is soon detached by the surrounding moisture. 



A new genus of ConvolvulacecB from Somali Land. 

 HiLDEBRANDTiA, Vatlce. — Sepala 4 decussatim imbricata inocqualia, 

 exteriora paulo majora post anthesin in alas orbiculares in pedunculum 

 late decurrentcs valvatim adpressas et fructum medio includentes 

 accrescentia. Corolla tubo infundibuliformi, limbo quadripartite. 

 Stamina 4 longitudine inaequalia tubo inserta demum exserta. 

 Ovarium biloculare, loculis exterioribus oppositis biovulatis. Styli 

 duo distincti ; stigmata lobata. Capsula bilocularis, loculis ovulo 

 altero abortive plerumque monospermis. 



Genus CresscB et Sedder<s proximum, hibitu singular!, florum tetra- 

 maria et sepalarum mirifica indole distinctissimum. Species unica 

 {H. africana, Vatke) Africse orientalis incola. 



Frutex aridus microphyllus, ramis spinescentibus, ramulis abbre- 

 viatis folia fasciculata et flores axillares gerentibus. Pedunculi fructi- 

 feri elongati filiformes. Calyx fructiferus Pteleoi samaram a^mulans. 

 Pili foliorum unicellularis medio affixi, crure altero apicem, altero basin 

 folii spectante. (Sitz. der ges. Aaturfor. Freundezu Berlin, 18th Jan., 

 1876 : reported in " Botanische Zeitung," 2nd June, 1876.) 



[J. M. Hildebrandt, no. 1515. — Somali Land, base of hills, not 

 common, April, 1875. — Vernac : Kail a asset. Leather is dyed red with 

 the juice of the root.] 



Reduction of Nitrates to Nitrites hy Bacteria. (Mensel in Ber. 

 Berl. Chem. Ges., Oct., 1875. Abstract in Amer. Journ. Sc. and 

 Arts, Jan., 1876.). — In support of this view the following facts may 

 be cited: — Water containing Bacteria and nitrates, but neither 

 ammonia nor nitrites, gives reactions of nitrous acid after standing 

 four days, while antiseptics either completely or partially prevent 

 the production of the nitrous acid. 



If freshly- distilled water be boiled with glucose and potassic 

 nitrate, it does not exhibit the presence of nitrites, even after long 

 standing, because Bacteria are absent. 



Putrefying {i.e., Bacteria-containing) albuminoids reduce nitrates 

 to nitrites. 



Heteromorphism in Epigoea. By Asa Gray, (Amer. Journ. Se. and 

 Arts, July, 1876.)— Flowers of Epigcea present four modifications of 

 andra3cium and gynoecium. 



