12 MISSOURI BOTANICAL OAKDEN BULLETIN 



bers, but is the reverse of this process. Mechanical agitation 

 also influences carbon assimilation. 



Burt, E. A. (Ann. Mo. Bot. Gard. 7:81-248), continuing 

 a monograph of the Thelephoraccae of North America, pre- 

 sents a comprehensive account of the genus Stereum. This 

 is a large genus, but the author finds the difficulties of iden- 

 tification, experienced by so many, greatly lessened after a 

 thorough study and analysis of the microscopically recogniz- 

 able organs or combinations of organs. The work includes 

 an elaborate key to the speeies ; and under each of the 77 

 American speeies discussed there are given the synonymy 

 and references to literature, full diagnosis, notes on occur- 

 rence, habits, and peculiarities, citations of specimens exam- 

 ined, etc. Among the 77 species referred to, twelve are new, 

 and five new combinations are included. In addition notes 

 are recorded on 10 imperfectly known .speeies and 20 speeies 

 are excluded from the genus. A continuation is promised. 

 The new species are 8. caespitosum, 8. saxitas, 8. pubexcens, 8. 

 rouicum, S. patclliforme, 8. Earlei, 8. magnisporum, 8. spu- 

 meum, 8. crumpens, 8. scpium, 8. hcterosporum, and 8. durum. 



Chambers, W. IL (Ann. Mo. Bot. Gard. 7:249-289) has 

 studied the intestinal organism Bacillus coli in respect to the 

 inhibition of growth by the products of its metabolism in cul- 

 ture on media containing and lacking carbohydrates. No 

 'autotoxiu" was found, but growth and death of the Bacillus 

 n dextrose bouillon is dependent on the hydrogen-ion concen- 

 tration of the medium, and if the latter is controlled the max- 

 imum count of cells may be more than ten times as great as 

 in cultures where the acidity is uncontrolled. He demon- 

 strates that there is no constant curve of growth and that 

 any such curve is dependent upon the reaction of the medium. 



Duggar, B. M. (Ann. Mo. Bot. Gard. 7:1-49) has intro- 

 duced a new culture solution for the higher plants consisting 

 of the lour salts, potassium nitrate, magnesium sulphate, cal- 

 cium sulphate, and soluble ferric phosphate. In the majority 

 of cases this combination has afforded a growth of wheat and 

 corn exceeding all other culture media. External conditions, 

 however, influence notably the value of any particular cul- 

 ture medium, and the writer is convinced that there is no sin- 

 gle "best" culture solution for the plants thus far studied. 

 Under ordinary conditions II-ion concentration may be a lim- 

 iting factor in the growth of plants in solutions containing 

 the acid phosphates. 



Duggar, B. M. (Ann. Mo. Bot. Gard. 7:291-298). Lt is 

 shown that peas deprived of their cotyledons during the- first 



