191T] AGEIOULTUBAI. BOTANY. 727 



years. It appears that a perceptible odor of gas near trees is a certain indica- 

 tion that they are being injured. 



Damage resulting to greenhouse crops and soil from escaping illuminating 

 gas, G. E. Stone {Florists' Ex. Ji2 {1916), No. 2, pp. 61, 85, fig. i).— Cases are 

 cited in which illuminating gas was known to travel for considerable distances 

 under frozen soil or more or less Impervious strata, or to escape otherwise and 

 injure vegetation in ways which are described, even when the concentrations 

 were hardly, if at all, noticeable to the sense of smell. Roses are extremely 

 sensitive to gas poisoning, and Easter lilies are greatly stunted thereby. Gas 

 in the soil may be taken up by water and carried to plants some distance away. 

 Sewer gas may be injurious if abundant, and certain paints give off gases 

 which are injurious. On the other hand, certain gases in low concentrations 

 are stimulating to growth. 



A plan is presented for the protection of plants near a leaking pipe, consist- 

 ing of a covering like an inverted trough for the gas main and connecting pipes 

 to carry the gases to the open air, where they do comparatively little damage. 



Leaf nectaries of Gossypium, E. L. Reed {Bot. Gaz., 63 {1917), No. S, pp. 

 229-2S1, pJs. 2. fig. 1). — The author describes certain nectar glands found on the 

 midrib and other principal veins of leaves of G. hirsutum. 



On the formation of nodules in the cortex of Hevea brasiliensis, G. Bbyce 

 {Dept. Agr. Ceylon Bui. 28 {1916), pp. 25).— Giving a somewhat detailed ac- 

 count of nodular and related structures in H. brasiliensis, the author states 

 that such nodules are produced as the result of an alteration In the content of 

 the latex vessels. This has not been referred to any parasitic organism and is 

 thought to be due to physiological changes in the latex, certain trees showing 

 a predisposition to develop this condition on tapping. Four types of nodule 

 are described. 



Globular shoots are to be distinguished from nodules, being formed by the 

 growth of latent buds and never forming a core or the large masses of woody 

 tissue sometimes resulting from nodule growth. 



Nodules formed around altered latex vessels do not appear on trees that have 

 not been tapped. These structures are formed on Hevea both in its native 

 habitat and In plantations. The condition is not infectious. 



Preliminary observations on the distribution of certain hymenomycetes 

 and on their probable relation to the ectotrophic mycorrhiza of phanerogams, 

 B. Peyeonel {Atti R. Accad. Lincei, Rend. CI. Set. Fis., Mat. e Nat., 5. ser., 26 

 {1911), I, No. 5, pp. S26-SS2). — Some details are given of associations, so far as 

 observed, between hymenomycetous fungi and woody forest plants of various 

 groups having ectotrophic but not endotrophic mycorrhiza. 



Studies in the physiology of the fungi.— Ill, Physical properties of wood 

 in relation to decay induced by Lenzites saspiaria, S. M. Zellee {Ann. Mis- 

 souri Bol. Oard., 4 {1917), No. 2, pp. 9S-164, pis. 16, fig. i).— The author follows 

 up the previous report (E. S. R., 37, p. 129) with an account of preliminary 

 experiments regarding the effects of L. swpiaria on wood of Pvnus palustris, P. 

 echvnata, and P. tceda, including a review of observation and opinion by others. 



He concludes that resin is no safe or practical index of the durability of the 

 three species of yellow pine investigated, except as its presence tends to exclude 

 moisture, which is favorable to the fungi. High specific gravity of the heart- 

 wood, on the other hand, materially increases resistance to these fungi on all 

 these pines. Specific gravity can be somewhat reliably estimated from the pro- 

 portion of the summer wood to the spring wood. The width of the growth rings 

 furnishes a further index of durability, which is greater in case of the nar- 

 rower rings. Age, or distance from the central pith, shows no relation to dura- 



