48 MORPHOLOGY, ETC., VASC. PLANTS [Bot. Absts. 



334. Popenoe, Wilson. The Tavocado in Guatemala. U. S. Dept. Agric. Bull. 743 

 69 p., 23 pi. 1919.— This bulletin gives the result of studies in the avocado plantings of. 

 Guatemala. The author states that probably in no other country are so many fine avo- 

 cados grown. Information is given on the extent of the industry, the uses made of the crop 

 and the climatic zones in which avocados are found to thrive. The author says that it is pos- 

 sible that the types, which should better be termed races, may have been derived from dis- 

 tinct species, but the wild prototype has not been found. The three races described are the 

 Guatemalan, the West Indian and the Mexican. Information is given concerning the origin 

 of choice varieties and a considerable number of varieties are described. Practical informa- 

 tion is also given as to cultural methods and marketing.— IF. H. Chandler. 



335. Riehl, E. A. Profitable chestnut growing. Amer. Nut Jour. 10: 27. 1919.— A 

 brief statement of best varieties now available. Figures on production in pounds for the 

 first 16 years of the life of a Boone chestnut are given.— R. H. Taylor. 



336. Van Trump, S. H. English walnut in Marion County, Oregon. Amer. Nut Jour. 10 : 

 13. 1919. 



MORPHOLOGY, ANATOMY AND HISTOLOGY OF 

 VASCULAR PLANTS 



E. W. Sinnott, Editor 



337. Brown, Forest B. H. The preparation and treatment of woods for microscopic 

 study. Bull. Torrey Bot. Club 46: 127-150. Fig. 1-6. 1919.— An investigation of the woods 

 of Hawaii led to the development of special technique for sectioning many of the hard tropical 

 woods. Information is presented as to use of microtome and knife. For sectioning, blocks 

 should be cut true. Air can be removed by alternate boiling and cooling, and for softening 

 hard woods it is safe to use strong hydrofluoric acid, which can be removed by washing for 4 

 days in running water; then blocks can be soaked in glycerine. Instructions are given for 

 imbedding in celloidin where this process is necessary. In using Schultze's method for 

 maceration, equal volumes of acid and water should be used for safety. For differential stain- 

 ing, Haidenhain's iron-haematoxylon is recommended with a counter stain of saffranin; for 

 soft cellulose tissues of bark Congo red is better than saffranin. Microchemical reactions 

 are given for cellulose, cellulose-lignin, gums, mucilaginous layers, essential oils, resins, gum 

 resins, fats, tannin, mineral crystals; and for chemical growth-rings when structural growth- 

 rings are lacking. Liquid penetration tests are of use for ascertaining the presence of tyloses 

 and gums. — P. A. Mum. 



338. Colani, M. Recherches sur les premieres phases du developpement de quelques 

 Combretacees et Barringtoniees. [Early stages of development of some Combretaceae and 

 Barringtoniaceae.] Thesis, Fac. Sci. Univ. Paris, 1914. [Through bibliographical note by A. 

 P. Allorge, in:Rev. Gen. Bot. [Paris] 30: 301. 1918.]— The Combretaceae studied (Terminalia 

 Catappa Willd., T. chebula Willd. and Poivrea sp.) are characterized by a slight growth in 

 length of the hypocotyl and a considerable elongation of the radicle. Germination in the 

 case of Barringtonia speciosa Willd. is similar to that characteristic of certain Myrtaceae in 

 the fact that there are no cotyledons, their function being assumed by the hypocotyl. The 

 cells of the hypocotyl are hypertrophied, and there is a considerable development of woody 

 tissue in the radicle. The cellular differentiation, first of the radicle, then of the plumule 

 (in Barringtonia), occurs during germination in the tissues of the hypocotyl. — C. E. Allen. 



339. Gut rin, Paul. Developpement de l'anthere et du pollen des Labiees. [Develop- 

 ment of the anther and pollen in the Labiatae.] Compt. Rend. Acad. Sci. Paris 168: 182-185. 

 1919. — The work of Warming on Mentha aquatica L. and of the author on the sages is believed 

 to be the only published work on the development of the anther and pollen in the Labiatae. 



