HOPKINS, A. D. 1905. The Black Hills beetle. 

 U.S. Bur. Ent. Bui. 56, 24 pp. 



HOPKINS , A. D. 1 906 . Barkbeetle depredations 

 of some fifty years ago in the Pikes Peak region 

 of Colorado. Ent. Soc. Wash. Proc. 8:4-5. 



HOPKINS, A. D. 1908. Notable depredations by 

 forest insects. U.S. Dept. Agr. Yearbook, 

 1907: 149-164. 



HOPKINS, A. D. 1909. Contributions toward a 

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HOPKINS, A. D. 1909. Practical information on 

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 U.S. Bur. Ent. Bui. 83, 169 pp^ 



HOPPING, GEORGE R. 1946. Control of the 

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HOPPING, GEORGE R. 1950. Timber types in 

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HORNIBROOK, E. M. 1942. Yield of cutover 

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Presents equation for estimating future yield. 



HORNIBROOK, E. M. 1948. Merchantable 

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HORNIBROOK, E. M. 1950. Estimating defect 

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Describes defects, particularly those due to 

 fungi (rots). Discusses methods useful in esti- 

 mating defects . 



HORNIBROOK, E. M. (See Taylor and 

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HORTON, K. W. 1956. The ecology of lodge - 

 pole pine in Alberta and its role in forest 

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Natl. Resources, Forestry Branch , Forest 

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HORTON, K. W. 1959. Characteristics of sub- 

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Discusses reproduction, community, de- 

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 mann spruce. 



HOTTES, F. C. 1961. A new species of Cinara 

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Discusses Cinara caliginosa, n. sp. on 

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HOTTES, F. C. 1961. A review and key of 

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 dae) occurring on Picea_. Great Basin Nat. 

 21: 35-50. 



HUBERT, ERNEST E. (See Weir and Hubert. 

 1918) 



HUGHES, JAY M. 1962. Pulp- and papermaking 

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 Forest Serv. Rocky Mountain Forest and 

 Range Expt. Sta. Paper 73, 48 pp. 



Engelmann spruce statistics. 



HUTCHISON, FRANK T. 1952. The effects of 

 woodpeckers on the Engelmann spruce beetle 

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 thesis. Colo. State Univ., Fort Collins. 



IVES, RONALD L. 1942. Atypical subalpine 

 environment. Ecology 23: 89-96. 



Reports on "Alpine rain forests" in Colorado 

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JACK, JOHN G. 1900. Pikes Peak, Plum Creek, 

 and South Platte Reserves. U.S. Geol. Surv. 

 Ann. Rpt. 20, 1898-99, Part V- Forest re- 

 serves: 39-115. 



JACKSON, A. BRUCE. (See Dallimore and 

 Jackson. 1948) 



JACKSON, H. S. 1917. A species of Chryso- 

 myxa new to North America. Phytopathology 

 7:78. 



This species causes a disease of the leaves 

 of Engelmann spruce. 



16 



