106 MORPHOLOGY, ETC., VASC. PLANTS [Bot. Absts., Vol. VI, 



the axis is not differentiated into nodes and internodes, that the gaps bear no relationship to 

 sporangiophoric traces, that they are not leaf-gaps but are related to mechanical efficiency, 

 and that the sporangiophores are not the morphological equivalent of leaves but are organs 

 sui generis. Throughout the plant the gaps are neither foliar nor ramular and have no mor- 

 phological value in questions of phylogeny. — W. P. Thompson. 



755. Beekman, H. 78 Preanger-houtsoorten, beschrijving, afbeelding en determinatie- 

 tabel. [78 Preanger timber species described and illustrated, with determination table.] 

 Mededeel. Proefsta. Boschw. Dept. Landb. Nijverheid en Handel Nederlandsch-Indie 5: 

 1-186. 60 pi. 1919.— See Bot. Absts. 6, Entry 83. 



756. Bergman, H. F. Internal stomata in ericaceous and other unrelated fruits. Bull. 

 Torrey Bot. Club 47: 213-221. 9 fig. 1920. — Numerous cases of the occurrence of internal 

 stomata are cited. These stomata remain mostly in an open condition and are not functional. 

 Their presence is explained by the fact that the fruit is a modified leaf, and their "persistence 

 must be regarded as an hereditary continuation of a stomata-producing tendency after the 

 leaf has lost its normal form and function." — P. A. Munz. 



757. Brown, Forest B. H. The refraction of light in plant tissues. Bull. Torrey Bot. 

 Club 47 : 243-260. 4 fi-Q- 1920. — In order to get the clearest definition of tissue outlines under 

 the microscope, it is necessary to know the refractive properties of these tissues. Refraction 

 can be measured under the microscope by the use of a gradient series of media of known 

 refractive powers, such as castor oil, clove oil, and naphthalene a monobromated. Direc- 

 tions are given for preparing such a series of media and the tissues for study. Methods of 

 illumination and examination under the microscope are also given. It is found that in a 

 given tissue, refraction may vary widely with imbibition and growth. To secure clearness 

 of anatomical details, such as pits and middle lamellae, it is desirable to have a medium with 

 the index of refraction below that of the tissue substance. — P. A. Munz. 



758. Browne, Isabel M. P. A third contribution to our knowledge of the anatomy of the 

 cone and fertile stem of Equisetum. Ann. Botany 34: 237-264. PI. 8-9, fig. 1-7, 1920.— The 

 vascular systems of the cones of Equisetum hyemale and E. giganteum are described and com- 

 pared with those of species previously studied. The cones of the different species can be ar- 

 ranged in a series, which is not to be considered a phylogenetic one, with respect to the degree 

 of reduction of the vascular system. This reduction tends more and more to obscure both the 

 relation of meshes (gaps) to traces and the alternation of traces in the successive whorls. The 

 author is of the opinion that the sporangiferous annulus is a recent development in the phy- 

 logeny of the genus, the sporangia having spread to regions which were not at first sporangif- 

 erous. — W. P. Thompson. 



759. Chodat, R. Le Hugueninia tanacetifolia. Bull. Soc. Bot. Geneve 11: 60-61. 1919. 

 — The flower and inflorescence of this species are described. — W. H. Emig. 



760. Chodat, R. La floraison du Lilium Martagon [The flowering period ofLilium 

 Martagon.] Bull. Soc. Bot. Geneve 11: 50-59. Fig. 1-5. 1919.— The changes that take 

 place in the flower from anthesis to the maturity of the fruit are described. — W. H. Emig. 



761. Cockayne, L. On the seedling form of the coral-shrub (Helichrysum coralloides 

 (Hook, f.) Berth. & Hook. f.). New Zealand Jour. Sci. Tech. 2: 274-278. July, 1919. 



762. Deshmukh, G. B. Polyembryony. Gardens' Bull. Straits Settlements 2: 258. 1920. 

 — Cases of polyembryony are recorded for Citrus decumana L. and Persea gralissima Gaertn. 

 — T. F. Chipp. 



763. Dodge, B. O. The life history of Ascobolus magnificus — Origin of the ascocarp from 

 two strains. Mycologia 12: 115-134. PI. 7-8, 28 fig. 1920.— "The ascocarp of Ascobolus 

 magnificus originates from a pair of morphologically distinct primordia — a large ascogonium 



