NOTES AND ABSTEACTS. 



395 



^. & 'El., Gloeosporium sp. from May-apple fmit, Colletotrichum nigrum 

 E. & H. and C. phomoides (Sacc.) Chest., with that fungus. Glomerella 

 gossypii readily infects sweet pea but will not infect the immature 

 apple. It would appear to be a physiological race of Glomerella rufo- 

 maculans. Colletotrichum gloeosporioides Penz., Gloeosporium sp, 

 from Populus deltoides, G. musarum and G. lagenarium (Pass.) E. & H. 

 do not infect apples or sweet peas even after puncture inoculations. 

 They therefore appear to be distinct species. — F. J. G. 



Syringra Julianae {Bot. Mag. t. 8423). — China. Family 

 Oleaceae; tribe Syringeae. Shrub, 3-4 feet high. Leaves ovate-ellip- 

 tic; inflorescence terminal, 2 inches in length; flowers white and lilac- 

 purple, 3-4 hn. long. — G. H. 



Tempepature Apparatus, An Electrical Constant. By 



W. G. J. Land {Bot. Gaz. pp. 391-399, Nov. 1911; 4 figs.).— The 

 author figures and describes an apparatus which will maintain a 

 definite constant temperature within very narrow limits for weeks at 

 a time. It is automatic, uses a minimum quantity of electricity, and 

 should cost about 15 dollars, or can be constructed for 3.75 dollars. 

 The thermostat is a strip of iron riveted to a strip of zinc. The free 

 end is in contact with a platinum-tipped adjusting screw. The heater 

 is a water- jacketed resistance coil of brass tubing and German-silver 

 resistance wire. 



The rise of temperature in the oven above a certain point is made 

 to open the switch by the separation of screw and strip of the thermo- 

 stat. When the temperature falls the strip again touches the screw. 



G. F. S. E. 



Tendrils, Breaking" Streng^th of. By W. D. Brush (Bot. Gaz. 



pp. 453-477, June 1912; 3 figs.).— The author found that tendrils 

 exposed to tension, and also having formed contact with a support, had 

 a much higher breaking strength (1007 grams average), as compared 

 with tendrils in contact only (651 gr.) and free tendrils (190 gr.). 

 Tension certainly increases strength of tendrils sometimes by as much 

 as 50 per cent, in the middle third of its length. By radial pressure 

 (obtained by a mercury column in an indiarubber tube enclosed by the 

 tendril), an increased breaking strength was obtained (990 grams as 

 compared with 727 gr.). Contact, pressure, and tension, all increase 

 the breaking strength. 



Ihe anatomical part of the paper shows that in passion flower 

 tendrils the cells of the xylem are increased both in number and thick- 

 ness by contact, and the walls of the pith, are much thickened in conse- 

 quence of tension. Tension acts as a stimulus perhaps by increased 

 hydrostatic pressure, perhaps by stimulation of the cell membrane, if 

 such membrane exists. — G. F. S. E. 



Timbers, Structural, Strengrth Values for. By McGarvey 

 Cline. {U.S.A, Dep. Agr., Forest Service, Circ. 189 ; Jan. 25, 1912). 



