NOTES AND ABSTRACTS. 



309 



citrange ' makes a beautiful vigorous-growing tree, and the fruit has more 

 nearly the flowers of the lemon. The tangelo is a new group of loose- 

 skinned fruits. It is a hybrid between the pomelo and tangerine, having 

 the easily removable rind of the tangerine and a flavour somewhat 

 sweeter than the pomelo. The experiments by the writers seem to have 

 been most interesting, and productive of far-reaching results. — V. J. M. 



Cliftonia, History of. By J. Britten (Joum. Bot. 514, pp. 282- 

 284; 10/1905). — A discussion on the introduction of this shrub, now 

 to be known as Cliftonia monophylla, but previously referred to Ptelea 

 and distributed as Walteriana caroliniensis. — G. S. B. 



Clover and Alfalfa, Experiments with. By J. H. Shepperd 

 (U.S.A. Exp. Stn. North Dakota, Bull. 65). — The results of some experi- 

 ments as to the best sort of clover to grow for hay, and the best way of 

 managing the crop in the severe climate of North Dakota. The shelter 

 of some corn stubble, preferably that of wheat, was found of great advan- 

 tage to the growing clover, and the best method of sowing appeared to be 

 to drill the wheat in rows running north and south, and the clover seed in 

 1| to 2 inch deep drills (not broadcast) from east to west. 



To regulate the rate of sowing, a mixture was made of 8 lbs. of 

 timothy grass seed, 5 lbs. red clover seed, and 4 lbs. rough salt per 

 acre, which proved most satisfactory. In a very dry season, when the salt 

 did not properly adhere to the seed, coarsely ground barley was sub- 

 stituted. 



The mixture of- timothy grass with the clover produces a larger 

 first crop, but if a second crop were taken pure clover would give the best 

 results. Clover grown in North Dakota from imported or southern- 

 grown seed produces very little fertile seed. 



Mammoth clover has so far proved less able than either the common 

 or the medium red to withstand the severe winters of this region, and the 

 formation of a thin crust of ice over the crop either by flooding or in 

 wheel tracks caused by carting operations seems fatal to any variety. 



One essential to the growth of clover in nearly every soil is the 

 presence of the nitrifying bacteria which produce tubercles on the roots 

 of the plants, and if these are not naturally present they must be 

 supplied, either by scattering infected soil from an old clover patch, or by 

 applying bacteria from pure cultures, such as are now being sent out by 

 the Bureau of Plant Industry in America. 



The experiments with alfalfa at the station indicate that it may ulti- 

 mately prove a successful crop in North Dakota, but the conditions are 

 not sufficiently favourable to justify farmers in devoting much land to it 

 as yet.— M. L. H. 



Cocoa-nut Palm, Bud-rot Disease (W. Ind, Bull. vol. vi. No. 3, 

 1905).— This is a summary of reports on this disease, which, under 

 different names, has been recognised since 1875 in the West Indies and 

 Central America. At first, and for some time, it was called " fever." 

 The conclusion arrived at by the U.S. Department of Agriculture is that 

 the primary cause of the disease is a parasitic fungus, described by Dr. 

 M. C. Cooke, in 1876, on a diseased palm sent from Demerara, and called 



