PERIODICAL LITERATURE 1049 



sufficient number to be a large factor in reproduction. He gives no 

 tables of germination of the seeds of the various species recovered from 

 the duff, relying upon Brewster's germination of the seed of western 

 white pine recovered from duff in northern Idaho, where even with 

 this most resistant species the germination was only from 2 to 20 per 

 cent. Careful germination tests on the seed recovered from duff would 

 have added a great deal to the value of the paper. 



The reviewer had the opportunity in July last to see the seed arti- 

 ficially stored in duff at the Priest River Experiment Station and was 

 impressed by the small number of viable seeds of most species at the 

 end of the second year. 



The forests of maritime pine along the Bay of Biscay and on the 

 sand dunes of the Landes of Bordeaux in France are often felled over 

 extensive areas, depending upon the seed in the soil for regeneration. 

 Although the seed of the previous year's crop is generally relied upon, 

 the delayed germination of previous years is also important. 



Extensive fires along the San Maurice River in Quebec and else- 

 where in Canada are followed by abundant reproduction, due probably 

 to seed storage in the duff. (Only on the bluff shores of the river! — 

 Ed.) The reproduction following fires that kill all vegetation in south- 

 ern forests is scanty and uncertain. This is probably due to the absence 

 of duff. 



Although Hofmann's researches add a flood of light to our present 

 knowledge of reproduction, they do not absolutely determine how long 

 the seeds of various coniferous species remain viable in duff in a per- 

 centage to be of importance in reproduction. This can only be deter- 

 mined by recovering seeds in duff and by later germination tests 

 ascertaining their reduction in viability for each year the seed is stored. 



J. W. T. 



Natural Reproduction from Seed Stored in the Forest Floor. Journal of 

 Agricultural Research, Vol. II, October, 1917. 



In the autumn of 191 3 Delavan collected the 

 Storage of Oak fruits of eight species of oak and hickory in the 

 and Hickory vicinity of Ann Arbor, Michigan. The fruits of 

 Seeds all species were thoroughly ripe and sound and 



were divided into four equal parts. One part was 

 placed in closed but not sealed fruit jars and deposited in a pit approxi- 

 mately one foot under the surface of the ground. The relative humidity 

 of the pit was high and the minimum temperature from late autumn 



