AGRICULTURAL BOTANY. 1031 



sbould Iio kept nt not I»>ss tliaii (Id ikt cent oT saturation, wliilo for timothy, 

 crostod dofjtail, and volvot grass it should in no case exceed »!() i)er cent of 

 saturation. A constant tein])orature of about '2r>° ('. gave the best results for 

 the rye grasses, timothy, and velvet grass, while for the others a variable tem- 

 perature of 18 hours at 25° C. and hours at 30° C. proved best. 



The influence of sea water on the germination of seed, S. Bircer (liof. 

 Cciithl., Bcihcftc. 21 {Will). 1. AM., No. S. pp. 263-280 ).—'in studying the dis- 

 tribution of jilants by means of ocean currents, the author was led to carry on 

 some experiments to test the effect of sea water on the germination of the seed 

 of 27 species of Scandinavian plants. Equal lots of seed were subjected for 

 30 days to sea water containing 3.4 per cent of salt, to fresh water, and 

 similar lots were placed to germinate between filter papers moistened with tap 

 water. 



With many species the sea water destroyed the vitality of the seed, while 

 with others it had little or no effect. In some instances more seed germinated 

 after being in sea water for .30 days than when in fresh water for a like period, 

 and some gave even higher percentages than \A'hen germinated directly between 

 the filter papers. The effect of the salt water depends upon its osmotic action, 

 which in turn is limited by the structure of the seed coats. It appears that 

 sea water may possibly exert some influence on the enzyms in the seeds. 



A tabular list is given showing the results of several investigators along the 

 line of experiments indicated. 



The germination of orchids, X. Bernard (Report of the Tliinl hitrnnitiounl 

 Conferenee, 1906, an Genetics. London: Roy. Hart. Soc., 1901, pp. 392-396, fig. 

 /). — The author gives an account of his investigations on the germination of 

 orchid seed, which seem to indicate that there is a close connection between the 

 germination of the seed of orchids and the species of fungi associated with 

 them. The fungi are capable of living apart from the roots of the plants, but 

 the orchids do not seem to develop except in the presence of the fungi. This 

 was shown by experiments in which the seeds of a number of orchids were 

 aseptically treated, placed in sterilized tubes with a nutritive solution, and kept 

 for months in suitable conditions of light and temperature. Under these condi- 

 tions the seeds become swollen and later they assume a green color, but their 

 growth remains insignificant. On the other hand, if the proper fungi are sown 

 with the seeds the germination begins almost immediately and proceeds in the 

 rcgnl.-ir manner. 



The author believes that orchids are by no means the only plants which are 

 benefited by some such association with fungi. 



The cross inoculation of Leguniinosae and other root-tubercle bearing 

 plants, W. B. Bottomley (Rjit. Brit. A.^soc. Adv. Sci.. 1906. pp. 7.7.^, 153). — 

 A hi'ief account is given of experiments conducted to test the possibility of 

 cross inoculation between the organisms found in the root tubercles of acacia, 

 alder, ehipagnus, and various lieguminosje. The acacia tul)ercles were obtained 

 direct from wattles from Western Australia, the other material being from the 

 Botanic Gardens, Regent's Park. The nodules were sterilized, cut under sterile 

 conditions, and small portions transferred to nitrogen-free cultures. After 

 inculiation for several days, the material was used to inoculate pots of sweet 

 peas and tares whicli were growing in sterilized sand. At the end of 4 weeks' 

 growth the plants were examined and it was found that every plant in the 

 inoculated set bore tubercles, wliile not a single one was found on the uninocu- 

 lated plants. 



The formation of slime or gum by Rhizobium leguminosarum, R. G. 

 Smtth (I'roc. Linn. tioc. X. ,S'. IFfl/c.s-, 31 (1901). pt. 2, pp. ;267/-,2.9.', ) .— The pro- 

 duction of slime by R. leguminosarum under certain conditions of cultivation 



