AGRICULTURAL BOTANT. 217 



the breadth of the corolla showed an average correlation with the length of the 

 corolla equal to 61 per cent. 



Abnorinal root formation by potato, O. Schlumbergek {Ber. Deut. Bot. 

 GeselL, 31 {1913), No. 1, pp. 60-63. figs. 2). — Following some observations by 

 Vochting (E. S. R., 11, p. 710), the author succeeded in developing experiment- 

 ally a root system at the basal end of a potato and in demonstrating correspond- 

 ing thickenings in the vascular portion of the tuber. 



Spontaneous detachment of twig's of some trees, M. de Vilmorin and R. 

 HiCKEL (Bui. Soc. Bot. France, 59 (.1912), No. 7, pp. 618-621).— The authors 

 give an account of observations made on autumn twig cast as exhibited in 

 various degrees by Populus alba, P. nipra pyramidalis, P. canadensis, Quercus 

 rohur pedunculata, Q. rubra, Alnus sp., Cunninghamia sinennis, and Taxodium 

 distichum, becoming total in the last named. It is suggested that the long wet 

 summer, abruptly succeeded by light frosts, may have been one of the determin- 

 ing influences. 



Physiological and economic sig'nificance of the structure of the tracheids 

 of conifers, I. W. Bailey (Abs. in Science, n. ser., 37 (1913), No. 91,9, p. SSJf).— 

 It is claimed that the so-called striated tracheids of conifers are a specialized 

 type of tissue structurally organized to resist compression. Studies showed that 

 cracking or splitting of tracheid walls in drying occurs sporadically and is con- 

 fined to the so-called summer wood. Injection experiments showed that the 

 membranes of bordered pits in freshly cut sapwood are perforated and are 

 permeable to gases, colloids, and finely divided solids held in suspension. 



Chondriosomes in living plant cells, A. Maximow (Anat. Anz., 43 (19 IS), 

 No. 10-11, pp. 241-21(9, figs. 9). — The author claims to have obtained a dear and 

 easy demonstration of chondriosomes in their various forms, stages, and rela- 

 tions (notably with starch and chloroplasts) by employing under high powers 

 the hairs from cucurbit seedlings. Illustrations and descriptions are given. A 

 brief bibliography is appended. 



Anatomical and physiological studies on water conduction by dicotyle- 

 donous leaves with particular reference to palmately veined tyiDes, A. Rippel 

 (Ber. Deut. Bot. GeselL. 31 (1913), No. 1, pp. 48-52).— Continuing the work of 

 E. Gerresheim with leaflets (E. S. R., 28, p. 629) and employing like methods, 

 the author carried out further anatomical and physiological investigations on 

 water transpiration in dicotyledonous leaves, particularly in the palmately 

 veined type, reaching the general conclusion that equalization of water and 

 solute pressures may occur by means of the cross and distribution channels, 

 both directly and through their walls, rendering any given portion of a leaf 

 in a measure independent of the main channel morphologically proper thereto. 

 It is thought, however, that, in case of such scarcity of water supply as may 

 have been common in such years as 1911, these morphologically main channels 

 may play an indispensable part in the life of a given portion of the leaf. 



The resistance offered by leaves to transpirational water loss, B. E. Living- 

 ston (Plant World, 16 (1913), No. 1. pp. 1-35, figs. 3).— This amplifies a report 

 previously noted (E. S. R., 28, p. 528). 



It is stated that the diurnal fluctuations in foliar transpiring power noted in 

 some leaves are the resultants of very different fluctuations in case of the two 

 leaf surfaces taken separately, as these may even be opposite in trend at a 

 given time. It is asserted also that the.se fluctuations in the transpiring power 

 in some cases are not fully accounted for by stomatal distribution and move- 

 ments, but that incipient drying (E. S. R., 27, p. 29) plays an important part. 

 The indexes of foliar transpiring power show a wide range, rendering gen- 

 eralization diflicult and uncertain at this time; but it is thought that further 



