NOTi-;s 88!> 



Perhaps the most important inorganic chemical constituent, so far 

 as plants are concerned, is lime. At least the presence or absence of 

 lime seems to produce a more noticeable difiference in the vegetation 

 than the presence or absence of other inorganic elements. Ry all odds, 

 tlie clearest and most reasonable hypothesis of the lime relation which 

 the reviewer has seen is that of Truog in his "Soil Acidity: I — Its re- 

 lation to the growth of plants." * In this he not only shows that each 

 species of plant has its own specific lime requirement, and why this is 

 so, but gives a table of the relative lime requirements of some of the 

 more important plants, including several forest trees. 



Fernald vigorously attacks the "dogma," as he calls it, that ignores 

 the influence of soil and rock formation outside of physical proper- 

 ties. He has no mercy on the mistakes into which Prof. A. H. Hutch- 

 inson^ is led through adherence to this dogma and blames Clements for 

 propounding the same theory. He leaves us with a definite impression, 

 and undoubtedly one which is fully justified, that failure to recognize 

 the influence soil factors, in particular the lime content, and to under- 

 stand the soil requirements of plants has retarded the development of 

 ecology. 



Barrinotox Moork. 



Notes on Reproduction of Western Yellow Pink i.\ Arizona 



An exceptionally heavy seed crop of western yellow i)ine on ilu' 

 Coconimo and Tusayan Forests in 1918. followed in 1919 by one of 

 the rainiest summers on record, has resulted in a seedling crop such as 

 has not been witnessed before since these Forests came under the ad- 

 ministration of the Forest Service. This situation has given rise to an 

 unequaled opportunity for the study of natural reproduction. In- 

 vestigations have shown that in virgin stands the number of seedlings 

 per acre in the openings is 100,000 to 150,000; in standard Forest 

 Service cuttings the number is 20,000 to 50,000, depending upon the 

 size of openings, while on areas bearing only one or two seed trees per 

 acre the number is usually less than 2.000. Another interesting obser- 

 \alion is the occurrence of local areas where the seed crop in 19 18 was 

 light, as indicated by the small number of cones on the ground. In 

 such cases the seedling crop is invariably light. 



Naturally forest officers are speculating as to the ultimate result of 



* Emil Truog: "Soil acidity: I — Its relation to the growth of plants." Soil 

 Science. Vol. 5, No. 3, pp. 169-196. March. 1918. 



° A. H Hutchinson: "Limitins: factors in relation to specific ranges of toleranci- 

 of forest trees." Bot. Gaz., Vol. 66, No. 6, pp. 465-493, December. 1918. 



