178 PHYSIOLOGY [Bot. Absts. 



Variations were found to occur in the chemical composition of the different cultures and 

 also in the biological characteristics. The latter included the ability to produce enzymes 

 capable of splitting different carbohydrates with the formation of gas and acid, and the abil- 

 ity to agglutinate with immune rabbit serum prepared with the organism as antigen. Varia- 

 tions were so great as to change one generally recognized species, Bacillus coli-communior , 

 into another, Bacillus coli-communis, by the use of fatty acids in the culture medium. Meth- 

 ods of work are included in the paper. — Chester A. Darling. 



1238. Howe, C. D. Making of the spruce tree. Canadian Forestry Jour. 14: 186. 1919. 

 —See Bot. Absts. 3, Entry 548. 



1239. Itano, Arao, and James Neil. Influence of temperature and hydrogen ion concen- 

 tration upon the spore cycle of Bacillus subtilis. Jour. Gen. Physiol. 1 : 421^128. 1919. — 

 Spores incubated at 5°C. for twenty days showed no apparent change except a slight swelling. 

 This swelling took place in all hydrogen ion concentration tested (Ph 1-13) . At 25° the spores 

 germinated in H ion concentration corresponding to the exponential range 5-10. The maxi- 

 mum germination was at Ph 7 and Ph 8. — /. M . Brannon. 



1240. Lundegardh, Henrik. Ekologiska och fysiologiska studier pa Hallands Vadero. 

 II. Till kannedom om strandvaxternas fysiologi och anatomi. [The physiology and anatomy 

 of shore-plants.] [Swedish, with English summary.] Bot. Notiser 1919: 1-39. 1919. 



1241. Phillips, R. W. Note on the duration of the prothallia of Lastraes filix-mas. 

 (Presl). Ann. Bot. 33: 265-266. 1919— See Bot. Absts 3, Entry 1113. 



GROWTH, DEVELOPMENT, REPRODUCTION 



1242. Appleman, Charles O. Root growth in cuttings. [Rev. of: Curtis, Otis F. 

 Stimulation of root growth in cuttings by treatment with chemical compounds. Cornell Univ. 

 Agric. Exp. Sta. Mem. 14: 71-138. 1918.] Bot. Gaz. 67: 100-101. 1919. 



1243. Gertz, Otto. Kallushypetrofier och nagra i samband dermed seraende anatomiskt- 

 fysiologiska forhallanden hos minerade blad. [Callus hypertrophies and some anatomical- 

 physiological conditions connected with them in insect-mined leaves.] [Swedish, with short 

 German resum6.] Bot. Notiser 1918: 121-139. Fig. 1-129. 1918.— Callus formations, which 

 had developed around borings of insect larvae in the leaves of Lonicera Xylosteum, L. Peri- 

 clymenum, Lamium album, Pyrus Malus, Belula verrucosa, Ranunculus repens, and Corylus 

 Avellana, are described and discussed. Reference literature, 29 articles. — P. A. Rydberg. 



1244. Reed, H. S., and R. H. Holland. The growth rate of an annual plant, 

 Helianthus. Proc. National Acad. Sci. [U. S. A.] 5: 135-144. Fig. 1-8. 1919.— The growth 

 of an organism depends on two groups of factors. One of these groups is essentially inter- 

 nal, and may be designated the genetic constitution of the individual; the other is essentially 

 external, and consists of the complex of environmental influences. If the growth rate of an 

 organism corresponds closely to the equation of autocatalysis, this fact would seem to indi- 

 cate that growth is predominantly controlled by internal factors. — This paper analyzes growth 

 data for fifty-eight sunflower plants from one lot of seed of unknown ancestry, which were 

 grown in the field under favorable and fairly uniform conditions at Riverside, California. 

 Height of stem was measured at seven-day intervals until elongation stopped. The varia- 

 bility in height as measured by the coefficient of variability increased rapidly for about two 

 weeks and fluctuated irregularly thereafter. The rate of growth increased rapidly to a 

 maximum, then rapidly declined as the flower head formed. The successive observed mean 

 increments in height corresponded closely to the theoretical values calculated from the 

 equation of autocatalysis. Temperature variations showed only a low and statistically 

 unreliable correlation with the growth rate, while atmometer readings gave no significant 

 evidence of such a correlation. When the plants are divided into four equal groups on the 



