628 EXPERIMENT STATION RECORD. 



electrified lots of seed. The galvanic current is believe<l to have acted upon the 

 solutions, and the seed were influenced in this manner and not directly. 



The germination of seeds of parasitic plants, E. Heinricher (Rev. Gen. 

 BoL, 21 {J 909), No. 2't9, pp. 329-334).— In a previous publication (E. S. R., 7, 

 p. 748) the author gave an account of the germination and structure of the 

 phanerogamic parasite Lathrfea, in which it was shown that the seed would not 

 germinate except in contact with its host plant. The author has since con- 

 tinued his studies with this class of phmts, particular attention being paid to 

 the holoparasitic and hemiparasitic plants. 



In the related genera, Bartschia and Tozzia, the author has found that with- 

 out the stimulus of the host the former germinates, but not the latter. Tozzia 

 never develops cotyledons underground, but it is 2 or 3 years in its subterranean 

 development, during which time it lives as a holoparasite. When the plant has 

 completed this stage it appears above ground, expands green leaves, flowers, and 

 dies within a few weeks. During this period it is only partially parasitic in 

 its habits. 



The action of potassium salts on the formation of saccharose in seeds, 

 G. De Plato (Ann. R. Staz. Cliini. Agr. Hpcr. Roma, 2. ser., 3 (1909), pp. 195- 

 202; Staz. Sper. Agr. Ital., JfS (1910), No. 1, pp. 97-lOJf) .—As. a result of ex- 

 periments conducted by the author it is claimed that the function of potassium 

 in vegetabh' nutrition bears an intimate relationship to the formation of carbo- 

 hydi-ates, and that to magnesium principally nuist be assigned the transporta- 

 tion of these carbohydrates and their subsequent accumulation in the seed, 

 while calcium seems to function mainly in the neutralization of the organic 

 acids formed during these nutrition changes. 



These seem to constitute the principal factors in the formation of the rela- 

 tively large amount of saccharose found in the seeds of peas. 



On the circulation of water in plants, Leclerc du Sablon (Rev. G6n. Bot., 

 22 (1910), No. 255, pp. 125-136). — From a review of the literature and his own 

 experiments the author was led to the conclusion that the ascent of sap in plants 

 is due to osmotic properties in the living cells. The transpiration of the leaves 

 and the absorption through the roots tend to produce difl'erences in rates of 

 pressure, but the principal role devolves upon the woody cells, which by their 

 osmotic power tend to keep a constant water supply. Transpiration can not 

 be held to cause the movement of water, since plants not transpiring still con- 

 tinue to retain the water pressure in the vessels. 



In conclusion the author states that the weight of a column of water occur- 

 ring in the vessels is supported by the cell walls and is not transmitted through 

 hydrostatic pressure to the cells below. The internal pressure in the vessels 

 is independent of the height and position in reference to the soil. 



The effect of some toxic solutions on mitosis, W. W. Stockberger (Bot. 

 Gaz., Jf9 (1910), No. 6, pp. Jf01-Jf29, figs. 7). — The investigation reported was car- 

 ried out in order to observe the process of nuclear and cell division under certain 

 definite conditions of physiological experiment with a series of toxic substances. 

 The toxic solutions experimented with were copper sulphate, phenol, and 

 strychnin. 



The results indicate that the toxic effect was first felt in the kinoplasm of 

 dividing cells, as shown by the loss of function and subsequent degeneration 

 of the achromatic figure. Large vacuoles arose in the cytoplasm, frequently de- 

 forming the achromatic figure and nucleus, and later the cytoplasm was disor- 

 ganized. The development of the chromatic figure was consequently inhibited, 

 but neither amitosis nor abnormal mitosis was observed. In the controls in 

 distilled water the cytoplasm became vacuolate, some of the nuclei were en- 

 larged, and occasionally the formation of the cell plate was interrupted. 



