NOTES AND ABSTRACTS. 



229 



influence exerted by the parasitism of nematode worms in roots 

 of certain of the Bromehaceae. Eeference is made to the work of 

 Vuillemin and Legrain, who state that at El Oued (a Saharan oasis) 

 the presence of Heterodera is necessary for the cultivation of beetroot in 

 that climate, and that the relation must be regarded " comme une 

 veritable symbiose." 



The main part of the paper is occupied with a description of the 

 remarkable morphological changes induced by the presence of 

 Heterodera in the roots of certain Bromeliads, and is an important 

 contribution to the literature of parasitism. — E. A. Bd. 



BPOOm-Pape. By T. W. Kirk, F.L.S., and A. H. Cockayne 

 (Dep. Agr. N.Z., Bull. 21; Feb. 1909; 4 figs.).— The illustrations 

 show the various stages of development in the broom-rapes, which 

 belong to the genus Orohanche, and all are true parasites, never pro- 

 ducing foliage-leaves or chlorophyll, but obtaining all their nourishment 

 from the host plant. The seeds of tlie broom-rape are almost the 

 smallest that are produced by any flowering plant ; they are very long- 

 lived, and may remain dormant for as long as ten years. 



The authors suggest several methods of prevention and extermina- 

 tion, and recommend that in paddocks where the parasite is troublesome 

 only those plants should be grown which are known to be free from 

 attack. A list of host-plants is appended. — V. G. J. 



BuPSeraceae. By A. Guillaumin {Ann. Sc. Nat. x. Nos. 4, 5, 6, 

 pp. 202-301; 62 figs.). — This family includes Crepidospermum, Pro- 

 tium, Tetragastris, Trattinickia, Canarium, Canariellum, Pachylohus, 

 Dacryodes, Santiria, Scutinanthe, Aucoumea, Triomma, Boswellia, 

 Bursera, Commiphora, Garuga, Canariastrum. The leaves, stem, 

 fruit, embryo, and germination are described of all but the last. The 

 two characteristics of the family are the presence of secretory canals in 

 the primary liber formed in the procambium, and the existence of two 

 ovules in the cell of the ovary. The Burseraceae are closely related 

 to the Eutaceae, Anacardiaceae, Meliaceae, and Simarubiaceae. 



S. E. W. 



Cabbagre GPOWingr. By E. E. Bennett {U.S.A. Exp. Stn. 

 Colorado, Bull. 143, March 1909). — As land in Colorado has been 

 irrigated, the character of the crops grown has changed, and cabbages, 

 potatos, and onions have taken the place of wheat, oats, and hay. 

 The best situation for cabbages is an altitude of between 6,000 and 

 9,000 feet. Irrigation is necessary when setting out the young cabbage 

 plants in the field, and the ditches are only filled in after two or three 

 appHcations of water have firmly sealed the plants in. The flea-beetle 

 IS the most serious insect pest, attacking the seedHngs, which are 

 therefore grown in covered frames. The alkaline character of the soil 

 may have something to do with the very small amount of club-root, 

 even though cabbages are grown continuously on the same soil — in one 

 case fourteen years in succession.— C. H. L. 



