232 HORTICULTURE jBot. Absts., Vol. V, 



cent ; maltose in a concentration of 10 to 15 per cent may give results that approach and some 

 times surpass those obtained with saccharose; lactose and glucose gave relatively good results 

 only in concentrations varying from 5 to 15 per cent while galactose gave passable results at 

 this concentration the optimum being between 5 and 10 per cent. Laevulose gave very poor 

 results. Distinct differences were to be observed in the pollen tubes germinated in the dif- 

 ferent sugars, and in the different concentrations. Accidental differences were observed in 

 some varieties in the position of the style with respect to the position of the anthers, and 

 differences in the number of styles and ovules in the pistils. Anthesis was found to take place 

 exclusively in day time, and mostly in the forenoon, the petals first expanding being the ones 

 first touched by the sun. Cleistoganry was often observed in good seasons, and dehiscence 

 took place mostly in the early forenoon under the direct guidance of the sun. Anthesis 

 appears to follow a centrifugal path along the branch. The influence of the position and alti- 

 tude of the tree and of grafting upon the time of flowering are also touched upon. A bibliog- 

 raphy is appended. — A. Bonazzi. 



1758. Marshall, Roy E. Pruning fruit trees. Virginia Polytech. Inst. Ext. Bull. 38. 

 37 p., 29 fig. 1919. — A popular discussion of the training and pruning of apple, peach, pear, 

 cherry, and plum trees with special emphasis on those phases of the subject of most practical 

 importance in eastern United States. — F. D. Fromme. 



1759. Maktix, J. N., and L. E. Yocum. A study of the pollen and pistils of apples in rela- 

 tion to the germination of the pollen. Proc. Iowa Acad. Sci. 25: 391-410. Fig. 163-166. 1920. 

 — The pollen of the five varieties of apples studied contains proteins or amino-acids, some pec- 

 tin, and occasionally small amounts of sugars at the time of pollination. Pollen grains ger- 

 minate in sugar solutions from pure water to 70 per cent, but most successfully at 2| per cent. 

 A temperature of 22°-25°C. was best. The stigma is papillate; pollen germinates when caught 

 between the papillae. The styles contain much cane sugar at some distance below the stigma. 

 No secretion was found on the stigma at the time favorable for pollination. — H. S. Conard. 



1760. Matsushima, T. Untersuchungen fiber die Wasseraufnahme bei abgeschnittenen 

 Zweigen. [Investigation of the water-absorption of amputated branches.] Jour. Coll. Sci. 

 Imp. Univ. Tokyo 43 2 : 1-27. 1919. — After an abstract of the literature of the subject, Matsu- 

 shima considers the relations of water-absorption to the Japanese art of arranging bouquets, 

 and reports the methods and results of his experiments. In these he used water, both tap 

 and distilled, and dilute acid and alkaline solutions, branches or sprays cut in the air and others 

 under water, and still others the cut ends of which were deliberately burned. His results, 

 as summarized at the end of the paper, are that in twigs cut off in air the decrease in water- 

 absorption is insignificant if the twigs have abundant wood, but that in plants with much 

 slime, milk or gum it is considerable: that burning the cut ends is especially favorable in 

 the slime, milk and gum carrying plants as thereby the stopping of the water-carrying vessels 

 is prevented: and that acids, especially the organic acids, increase the water-absorption 

 while alkalies decrease it in ordinary plants, whereas in milk, slime and gum containing 

 twigs the reverse is true. — G. J. Peirce. 



1761. Munn, M. T. Spraying lawns with iron sulfate to eradicate dandelions. New York 

 Agric. Exp. Sta. [Geneva] Bull. 466: 21-59. PL 1-6. 1919. — Experiments made at Geneva, 

 New York, demonstrate that dandelions (Taraxacum officinale and T. erythrospermum) may 

 be eradicated from lawns at small expense and without material injury to the grass by spray- 

 ing four or five times during the season with a solution prepared by dissolving 1.5 to 2 pounds 

 of iron sulfate in one gallon of water. Spraying should be supplemented by the use of fertil- 

 izers and the application of grass seed in the spring and fall of each year. With proper man- 

 agement a lawn may be kept practically free from dandelions by spraying every third year. 

 The cutting-out method of fighting dandelions is laborious and ineffective unless the greater 

 part of the root is removed. A study of seed production in Taraxacum officinale shows it to 

 be parthenogenetic. — F. C. Stewart. 



