DISEASES OF PLANTS. 1049 



Seed dispersal, W. J. Beal (Xew York: Ginn $■ Co., 1898, pp. 90, figs, &?).— This 

 handsome little book contains accounts of how various plants migrate through their 

 adaptive arrangements for seed dispersal. 



Absorption of water by rice seed, H. Ando (Imp. Univ. Col. Ayr. [Tokyo] Bui., 

 Vol. 3, Xo. 5, pp. 474-478).— In order to ascertain the amount of water necessary for 

 germination and the length of time required for rice seeds to absorb a sufficient quan- 

 tity for their germination, the author conducted a series of experiments, from which it 

 appeared that on the average 22.57 per cent of water by weight is required to sat- 

 urate rice seeds, and this quantity of water is absorbed in 240 hours at a compara- 

 tively low temperature. This amount of water is said to be much more than 

 sufficient for germination, and from the experiments it appears that soaking the 

 seed for from 5 to 7 days is sufficient for them to absorb enough water to facilitate 

 their germination. 



The field mustard (Sinapis arvensis) and its destruction, a. Staks ( Tijdschr. 

 Plantenziekten, 4 (1S9S), Xo. 2, pp. 31-35). 



New South Wales weeds, J. H. Maidkn {Ayr. da:. Xew South Wales. 9 (1898), 

 Xo. 12, pp. 1371-1374, pis. 2). — Notes are given on Cyperiis rotundas, or nut grass. 



A new weed on western ranges, L. H. Dewey (Erythea,7 (1899), No.l,pp,10, 

 11). — The presence of Molucella Irevis on ranges in Oregon and Arizona is noted. The 

 plant is an annual and stock will not eat it, hence it may become a troublesome 

 weed. 



Destruction of noxious 'weeds (Queensland Ayr. Jour., 4 (1899), Xo. 2, pp. 149 

 150). — Notes the use of iron and copper sulphates for the destruction of charlock and 

 other weeds, aud states that extensive experiments with these fungicides are to be 

 conducted at Newcastle-on-Tyne. 



DISEASES OF PLANTS. 



Mycological notes, B. D. IIalsted {Bui. Torrey Bot. Club, 20 (1899), 

 No. 1, pp. 12-20, ficjH. 2). — The author gives miscellaneous uotes ou a 

 number of fungi, their influence upon their hosts, etc. He reports the 

 presence during the month of May of a remarkable development of 

 Botrytis vulgaris on garden peonies. The outer leaves of the plant 

 were in a healthy condition, while all the inner ones were brown, life- 

 less, and overgrown with the fungus. A long-continued period of 

 rainy weather preceding the discovery of this attack is thought to have 

 had some influence upon the severity of the attack. 



A rust of Phlox subulata is reported as quite abundant in the vicinity 

 of New Brunswick, New Jersey. This rust is specifically different from 

 Puccinia plumbaria, which is found abundant on Phlox divaricata and 

 other species, but it agrees closely with Puccinia gilece, a well-known 

 western form. 



Attention is called to the effect of sunlight on the development of 

 leaf blight of cherry. Figures are given in which it is shown that the 

 part of the leaf receiving the greatest illumination was most severely 

 affected, and it is stated that possibly the exposure of the leaf to an 

 excess of light brought about a scalding or browning of the tissue, and 

 this in turn might prepare the way for better entrance of the fungus. 



The influence of fungi on the fruitfulness of the host plant is shown 

 in the effect produced by asparagus rust upon its host. It seems that 

 the attacks of the fungus weaken the plant materially, reducing the 



