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1 903 1 CURRENT LITER A TURE 4 4 1 



The Cycadofilices, generally recognized as a group intermediate 

 f between ferns and cycads, have been known only by their habit and ana- 



tomical structure. The discovery of seeds belonging, in all probability, to 

 Lyginodendron^ lends strong support to the view that the Cycadofdices form 

 the connecting link between ferns and cycads. Botanists must be prepared 

 to find that many of the plants now classed under Cycadofilices possessed 

 seeds and that many of the "fern fronds" of paleobotanists belong to sper- 



matophytes. — Charles J. Chamberlain. 



Darwin and Pertz have confirmed their previous results in establish- 

 ing artificial rhythm in plants'" through subjecting them to periodically 

 reversed stimulation by means of the intermittent clinostat. Both heliotropic 

 and geotropic stimuli were used, the experiments with light being most 

 successful. Rythmic curvatures were induced for an hour or more in Phala* 

 rts cafuxriensis by 15-minute reversals of stimulation ; the clinostat was then 

 stopped, but the periodic response continued, showing one or two reversals 

 > of bending. Alternate unequal stimuli induced persistent unequal curva- 



ture.— C. R. B. 



The development of lateral members of Linaria spuria has been studied 

 by Vochting/' This plant is especially suitable for testing Schwendener's 



contact theory," viz., that young organs are laid down in contact with the 

 older, because m L, spuria the leaves are in whorls, while the flowers are 

 arranged spirally. Vochting bases his inferences on the transition region of 

 the stem, and on the anomalies presented by the flowers. He comes to the 

 same conclusion as in an earlier paper on Cactaceae, that the contact theory 

 alone will not account for the position of lateral organs, and falls back on 



inner causes" as an explanation of the phenomena observed. — M. A. 



Chrysler. 



Black'man " has shown that the behavior of germinating teleutospores of 

 Uromyces, Puccinia, and Phragmidium depends upon the amount of water in 

 which the spores are sown. With a thick layer of water, the germ-tube 

 grows until it has exhausted the material of the spore, and then dies, no 

 sporidia being produced. But if the water layer is sufficiently thin for the 

 tube to reach the air before its growth ceases, it immediately produces spo- 

 ridia in the usual way. When the teleutospores are germinated in moist air 



^Oliver, F. W., and Scott, D, H., On Lagenostoma Lomaxi, the seed 

 Lyginodendron. Read before Roy. Soc. London, May 7, 1903- 



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'° Darwin ANDPERTZ,On the artificial production of rhythm in plants,with a note 

 on the position of maximum heliotropic stimulation. Annals of Botany 17:93-106. 

 1903. See also /^/^/. 6:245. 1892. 



"Vochting, Hermann, Ueber den Sprosscheitel der LinaHa spuria. Jahrb. Wiss. 

 ^ot. 38: 83-118. ph. 2-s. 1902. 



"Blackman,V. H., On the conditions of teleutospore germmation and of spo- 



ridia formation in the Uredineae. New Phytologist 2 : 10-14. pi /. I903- 



