VI COXTEXTS volume lxx 



Swelling of agar in solutions of amino acids and 



related compounds (with six figures) - - D.T. Mac Don gal and 



H.A.Spoehr 268 

 Early stem anatomy of Todea barbara (with plates 



XXIII-XXYI) -------- James E. Cribbs 279 



Subcortical formation and abnormal development 

 of stomata in etiolated shoots of Opuntia 

 Blakeana (with plates XXYII-XXX and one 

 figure) ------:--- /. Q. Brown 295 



Composition of gases in intercellular spaces of 

 apples and potatoes. Contributions from the 

 Hull Botanical Laboratory 271 (with one 

 figure) -._. J. R. Magness 308 



North x\merican species of Taraxacum. Contribu- 

 tions from the Hull Botanical Laboratory 272 

 (with plates XXXI-XXXIII) - - - - Earl E. Sherfi 329 



Viscosity values of protoplasm as determined by 



microdissection -------- William Seifriz 360 



Grouping and mutation in Botrychium. Contribu- 

 tions from the Hull Botanical Laboratory 273 

 (with eleven figures) ------ C. /. Chamberlain 387 



New or noteworthy Porto Rican fungi (with four 



figures) --------- F. L. Stevens 399 



Flower and seed of Hedyosmum nutans (with plates 



XXXIV-XXXVI) ------- J.G.Edwards 409 



Some characters of xylem tissue in Cycads (with 



plates XXXVII, XXXVIII and one figure) - H. B. S if ton 425 



Development of embryo of Gnetum (with plates 



XXXIX-XLI and one figure) - Hulda I. Raining 436 



A morphological study of Cicer arietinum (with 



plates XLII-XLIV ------- Theo. Holm 446 



Correlation work in peat-land problems - - - A. P. Dachnowski 453 



Origin of mechanism of heredity. Contributions 



* 



from the Hull Botanical Laboratory 274 - - Merle C. Coulter 459 



Briefer Articles — 



Sectioning hard woody tissues ----- LaDema M. Langdon 82 



Camphorina vs. Cinnamomum ----- E. D. Merrill 84 



Relation of flax to varying amounts of light - /. Adams 153 



