Current Literature. 281 



climatic and soil conditions seems much closer to the actual 

 determinations than one based upon climate alone as that of Mayr 

 outlined above in this number of the Quarterly. 



C. D. H. 



Experiments in Blueberry Culture. By Frederick V. Coville. 

 U. S. Department of Agriculture. Bureau of Plant Industry. 

 Bulletin 193. Washington, D. C. 1910. 



Coville's paper throws many interesting side lights upon the 

 characteristics of peaty soils. He distinguishes "upland peat" 

 from bog peat, the former being "a non-paludose deposit of 

 organic matter, chiefly leaves, in a condition of suspended and 

 imperfect decomposition and still showing its original leaf struc- 

 ture, the suspension of decomposition being due to the develop- 

 ment and maintenance of an acid condition which is inimical to the 

 micro-organisms of decay." Leaf mold is separated from the 

 above by the facts that decomposition has proceeded so far that 

 leaf structure has disappeared and that it is neutral or alkaline in 

 reaction, at least so far as tested. The upland peat of the char- 

 acter defined above is found beneath laurel (Kalmia) thickets, 

 beneath scrub pine (P. virginiana), and doubtless other pines as 

 well, being the leaves of these species imperfectly decayed owing 

 to their acidity. Freshly fallen oak leaves also were found to be 

 acid (0.4 normal). Oak leaves one year old and two years old 

 were 0.006 and 0.002 normal respectively, in acidity, that is, in 

 such proportions of the "normal solution" of chemists. Oak 

 leaves several years old beneath those of acid reaction were alka- 

 line and contained 3.5 per cent, of lime. It is suggested that the 

 lime in the leaves, remaining constant in amount and probably 

 having been changed to a more soluble state, had neutralized the 

 remaining acidity. The material then becoming alkaline, the 

 bacteria of decay found congenial conditions and so decomposition 

 proceeded with greater rapidity until real leaf mold had been 

 formed. The author suggests that a similar sequence of events 

 takes place in drained bogs and muck lands which, when first 

 plowed, will grow only acid resisting crops, but later as their 

 acidity disappears, they attain a high degree of fertility. 



Coville punctures a theory of ecologists in relation to the diverse 

 habitats of certain heath plants, namely, the one a peat bog, the 



