JANUAKT 29, 1915] 



SCIENCE 



179 



Fiber Measurement Studies; Length Variations: 

 Where They Occur and Their Relation to the 

 Strength and Uses of Wood: Eloise Gerrt. 

 I. The results of the study of one white pine 

 tree indicate: (These are 'based on the measure- 

 ments made on 6j600 fibers from 66 specimens.) 



1. The length of fibers varies with their posi- 

 tion in the tree. 



A. In (1) a disk from the butt (age 250 years, 

 distance above the ground approximately two 

 feet) and in (2) a disk near the top (about 82 

 feet above the ground) the shortest fliers were 

 found near the pith. An increase in length was 

 apparent from the center outward. This was 

 somewhat irregular (slides). No constant fiber 

 length was attained. 



B. In 26 bolts, taken at about 2i to 3 inches 

 from the pith, at 4-foot intervals between the 

 butt and the top of the tree, a tendency toward 

 an increase in average fiber length was apparent 

 for about two thirds of the height of the tree. 



2. TJie relation tetiveen the flier length and 

 the strength values of the wood was indetermi- 

 nate; no direct effect dependent on length alone 

 could he found. The following indications were 

 obtained, however: 



A. From butt to top the S. G. and strength de- 

 creased but the average fiber length increased. 



B. In some loblolly pine the late wood was 

 about twice as strong as the early wood; the rela- 

 tive fiber length was as 2.69 is to 3.03 mm. 



C. In Eotholz the fibers are also stronger (in 

 compression) and shorter than those in normal 

 wood. 



That is, the shortest but at the same time the 

 thickest-walled fibers were present iu the strong- 

 est specimens. 



II. The general range of variation in fiber 

 length was not found to be greater within the 

 species than in the individual tree. 



1. Longleaf pine {Finus palustris) (1,700 meas- 

 urements of 15 specimens). 



2. Douglas fir (Fseudotsuga taxifolia) (900 

 measurements of 5 specimens). 



The longest fibers were found in the earliest 

 springwood; the length then decreased gradually 

 and the shortest fibers were present in the last 

 formed layers of the ring. 



III. Certain general relationships also noted: 

 1. The root fibers of longleaf pine and white 



pine were found to have a fiber length as long as 

 or even longer than that of the trunk fibers. This 

 may enable the pulp mill to utilize stumps ob- 



tained where land is being cleared or the chips 

 from which resin has been extracted for a strong 

 craft pulp. 



2. In general the hardwoods or angiosperms 

 have a shorter fiber than the softwoods or gymno- 

 sperms. All other things being equal, the strength 

 of a pulp varies with the length of the fibers com- 

 posing it. 



3. The early or springwood fibers are always 

 longer than the late or summerwood fibers. The 

 data obtained from about 80 specimens indicated 

 that less than one fourth of the fibers found in 

 every hundred macerated fibers were summerwood. 

 In two cases the summerwood fibers made up 

 about one third of this amount; in both cases this 

 large number of fibers was found in wood from 

 very low down in the tree. The per cent, and 

 character of the summerwood fibers are signifi- 

 cant factors in determining the character of a 

 wood to be used for pulp. 



Changes in the Frvdt Type of Angiosperms Co- 

 incident with the Development of the Herbace- 

 ous Habit: E. W. Sinnott and I. W. Bailey. 

 Angiosperms vrith fleshy fruits are almost in- 

 variably trees, shrubs or climbing herbs. Terres- 

 trial herbs practically always have dry fruits. 

 Herbs seem to have been developed from woody 

 plants in relatively recent times. It is therefore 

 evident that with this change in habit there must 

 have been changes in many families from a fieshy 

 type of fruit to a dry one. This is apparently 

 due to the fact that most frugiverous birds are 

 reluctant to feed on the ground and that herbs 

 have consequently been obliged to develop new 

 methods for seed dispersal. 



Some Effects of the Brown-rot Fungus upon the 

 Composition of the Peach: Lon A. Hawkins. 

 This paper describes the results of several series 

 of experiments on the effect of the brown-rot 

 fungus upon certain carbon compounds in the 

 peach fruit. In the experiments one half of the 

 peach was inoculated with the fungus, while the 

 other was retained sterile under the same moisture 

 and temperature conditions as a control. At the 

 end of two or three weeks the two portions were 

 analyzed. It was found that in the rotted por- 

 tion the pentosan content was practically the 

 same as in the sound half; the acid content was 

 increased; the amount of alcohol-insoluble sub- 

 stance which reduces Fehling's solution when 

 hydrolyzed with dilute HCl was decreased; the 

 total sugar content was decreased, while the cane 

 sugar practically disappeared. 



