No. 1 , August, 1920] MORPHOLOGY, ETC., VASC. PLANTS 75 



569. Miller, E. C. Development of the pistillate spikelet and fertilization in Zea mays L. 

 Jour. Agric. Res. 18: 255-265. PI. 19-32. 1919. — Study made on three varieties of maize: 

 Pride of Saline, Freed White Dent, and Shorrod White Dent. The development of the pis- 

 tillate spikelet is briefly described. — In the development of the embryo sac there is no de- 

 generation of megaspores; the megasporocyte nucleus by three divisions gives rise to the eight 

 nuclei of the sac, as in Lilium. The antipodals multiply and form a tissue of from 24 to 36 

 cells in the base of the sac. — The silk is receptive to pollen not only at the stigmatic surface, 

 but also along the greater portion of its length. The pollen tube may penetrate the silk at once 

 or grow along the surface for some distance and penetrate later. Around the two vascular 

 bundles of the silk are sheaths of cells with rich contents; it is between these cells that the tube 

 grows. The tube penetrates into the embryo sac and .liberates the two male nuclei, which 

 are formed before the shedding of the pollen grain. One of them fuses with the egg nucleus, 

 while the other unites with the two polar nuclei, which do not fuse until this time. About 

 26 to 28 hours elapse between pollination and fertilization. — The endosperm develops rapidly, 

 filling the sac with tissue in 36 hours; the embryo by this time has 14 to 16 cells. [See Bot. 

 Absts. 4, Entry 679.]— L. W. Sharp. 



570. Miller, Ward L. Polyxylic stem of Cycas media. Bot. Gaz. 68: 208-221. 11 fig. 

 1919. — The normal cylinder begins its differentiation as high up as the meristem, the others 

 beginning theirs successively lower, and each one in the cortex outside the next inner cylinder. 

 Protoxylem and protophloem are developed during the early activities of the normal cylinder, 

 the protoxylem elements usually being scalariform, as in the primary xylem. The secondary 

 xylem is characteristically pitted. In the first cortical cylinder most of the xylem elements 

 are pitted, neither protoxylem nor protophloem being observed. In both cylinders there is 

 a relatively large number of suberized bast fibers. All cortical cylinders are similar in origin 

 and development, and probably are related in appearance to alternating periods of rest and 

 activity. — H. C. Cowles. 



571. Morvillez, F. L'appareil conducteur foliaire des Legumineuses : Papilionacees et 

 Mimosees. [Leaf traces in the Leguminosae: Papilionatae and Mimosoideae.] Compt. Rend. 

 Acad. Sci. Paris 168: 787-790. 9 fig. 1919. — -Ten types of vascular supply in the petioles of 

 members of the sub-families Papilionatae and Mimosoideae are described and figured. In a 

 previous paper (Compt. Rend. 167: 205. 1918) the leaf traces in the Caesalpinioideae were 

 described. — The three sub-families of the Leguminosae present types of leaf traces with med- 

 ullary strands similar to those of the Chrysobalanoideae of the Rosaceae; this character is 

 encountered even in such widely separated genera as Swarlzia, Affonsea and Bocoa. The 

 most highly specialized forms possess the simpler trace. — Subdivisions of the Papilionatae 

 agree in leaf trace anatomy with the exception of the Astragaleae, in which are encountered 

 the various types characteristic of the other tribes. This may represent a stock from which 

 the others have been derived. Moreover, the Astragaleae, through the Sophoreae, seem to 

 be related to types possessing medullary strands, thus constituting an assemblage of closely 

 related forms, to which are attached the different sub-families of the Leguminosae. — F. B. 

 Wann. 



572. Nelson, J. C. Monomorphism in Equisetum Telmateia Ehrh. Amer. Fern Jour. 

 9:93-94. 1919. 



573. Nelson, J. C. Another "freak" Equisetum. Amer. Fern Jour. 9: 103-106. PI. 6. 

 1919. — Linn County, Oregon, is a new locality for Equisetum fluviatile L. Among the speci- 

 mens collected was one, E. fluviatile var. polystachyum, which had 31 branches of the two 

 upper whorls bearing strobiles at the tip. — F. C. Anderson. 



574. Sahni, B. On certain archaic features in the seed of Taxus baccata, with remarks 

 on the antiquity of the Taxineae. Ann. Botany 34: 117-134. 7 fig. 1920.— It is suggested that 

 the Palaeozoic seeds Cardiocarpus, Cycadinocarpus , Mitrospermum, and Taxospermum, all 



