No. 2, September, 1921] MORPHOLOGY, ETC., VASC. PLANTS 135 



MORPHOLOGY, ANATOMY AND HISTOLOGY OF VASCULAR PLANTS 



E. W. SiNNOTT, Editor 



(See also in this issue Entries 639, 730, 755, 892, 916, 984, 1077) 



864. Anonymous. [National Herbarium, Sydney, exhibit.] Proc. Linn. See. New South 

 Wales 44: 820-821. 1919 [1920].— Note on the exhibit of specimens from the National 

 Herbarium, Sydney, and elsewhere, showing synanthy and syncarpy. — Eloise Gerry. 



865. Anonymous. [Rev. of: Arber, Agnes. The leaves of the irids and the phyllode 

 theory. (Paper read before Sect. K of the British Assoc. Adv. Sci., August, 1920.)] Jour. 

 Indian Bot. 2 : 58-59. 1921. 



866. Dunn, Grace A. Note on the histology of grain roots. Amer. Jour. Bot. 8 : 207-211. 

 Fig. 4- 1921. — Characteristic openings were observed in the root cortex of Zea mays and 

 Triticum vulgare when grown in water culture. In wheat these openings always appeared 

 whether the culture solution was well or poorly balanced and under a wide range of tempera- 

 tures. Wheat roots grown in sand or soil, however, showed no such openings. In corn, 

 similar results were obtained in the winter, but in summer, when the temperature was high 

 and growth rapid, fast-growing roots in sand and in soil also showed large openings. It is 

 suggested that the openings appear when the oxygen supply is deficient, as it is likely to be 

 in water culture and in all cases where growth is very vigorous and rapid. — E. W. Sinnott. 



867. Fritsch, Karl. tJber den Begriff der Anisokotylie. [On the concept of anisocotyly.] 

 Ber. Deutsch. Bot. Ges. 38: G9-73. 1920. — The term anisocotyly was proposed by the author 

 in 1904 for the characteristic behavior of the cotyledons of seedlings of certain members of 

 the Gesneriaceae, particularly of the genus Streptocarpus. In these plants, and according 

 to the author in none of the plants of other families in connection with which the term has 

 since been used, 1 of the 2 cotyledons, which are approximately equal in size in the seed, 

 develops into a foliage leaf while the other stops growing very soon after germination. He 

 believes that in other cases where the term has been used in reference to unequal size of the 

 cotyledons this inequality exists in the embryo before germination and is due to the cotyledons 

 being bent in the seed or otherwise arranged so that the development of one is mechanically 

 hindered. This condition exists in species of Gnetum; in certain genera of the Cruciferae, 

 IMoraceae, Phytolaccaceae, Nyctaginaceae, Capparidaceae, Malpighiaceae, Dipter- 

 ocarpaceae, Cactaceae, and Melastomaceae; and in some species of Thunbergia and 

 Coreopsis. Cases such as that of Ranunculus ficaria, where a single cotyledon is formed by 

 the growing together of 2, have nothing to do with anisocotyly. He reiterates, on the basis 

 of observations of J. Brunnthaler in South Africa, his formerly expressed belief that true 

 anisocotyly, as found there in species of Streptocarpus, is connected with the habit which these 

 plants have of growing upon precipitous slopes. — R. M. Ilolman. 



868. McDouGALL, W. B. Thick-walled root hairs of Gleditsia and related genera. Amer. 

 Jour. Bot. 8: 171-175. Fig. S. 1921. — Root hairs of Gleditsia triacanthos become thick- 

 walled and brown within a few days after they are produced. They persist as long as does the 

 root epidermis. These root hairs are regarded by the author as xerophytic structures, per- 

 sisting from a time when the species grew under xerophj'tic conditions. Trees with these 

 root hairs have neither bacterial nodules nor mycorrhiza. Gymnocladus and Cercis some- 

 times have thick-walled brown root-hairs, but not as characteristically as does Gleditsia.^ 

 E. W. Sinnott. 



869. McNair, James B. The morphology and anatomy of Rhus diversiloba. Amer. 

 Jour. Bot. 8: 179-191. PI. 2. 1921. — The morphology and anatomy of the leaf, stem, root, 

 and flower of this species are described in detail. — E. W . Sinnott. 



