ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 471 



sperm to perform its part in the process. 5. It seems to be due either 

 to some hindrance interposed by the egg, or to the interaction of egg 

 and sperm As no means of hindrance was detected, it is presumed that 

 there is an interaction between egg and sperm, probably of both physical 

 and chemical nature. 6. The movements of fern sperms are complex 

 and varied. Their reactions depend on their physiological state, and 

 thus partly on their past experiences. 7. Sperms have a mechanism of 

 response called into play by change of conditions, or by an interference 

 with the normal movements. In such cases they perform a series of 

 complex movements until they die or free themselves from the stimulus. 

 8. Orientation of the sperms in both the positive and negative reactions 

 is usually attained by a series of gradual swingings of their anterior ends 

 accompanied by a rotation on their axes, and not by a sudden turning 

 toward or away from the stimulant. 9. The observed movements and 

 reactions seem due to the effect of the stimulant on the organism as a 

 whole, and not to the action of different concentrations of the stimulant 

 on local parts of the organism. 10. The reactions of fern sperms thus 

 seem to be of the same kind as those described for Protozoa. 



Dryopteris Hybrids in North America.* — M. Slosson refers to R. C. 

 Benedict's paper on the hybrids of Dryopteris in the United States, where 

 it is shown that fifteen hybrids are possible between the six species, 

 D. cristata, D. Glintoniana, D. Goldiana, D. marginal/is, D. spinulosa 

 and D. intermedia. Twelve of these have been described. Two remain 

 over for study. And the fifteenth, D. Glintoniana x margin alis, is now 

 described by M. Slcsson, and its comparative characters are pointed out. 



Orientation of Botrychium Lunaria.f — L. Lammermayr publishes 

 a note on Botrychium Lunaria. He recalls how Prantl divided Botry- 

 chium into two groups according to the position of the stomata on the 

 sterile frond. In Eu-Botrychium the stomata are situated on both sides 

 of the frond ; in PhyUotrichum only on the underside. This doubtless 

 depends on the orientation of the frond to light. In Phyllotrichium the 

 frond is horizontal and dorsi ventral, in Eu-Botrychium (including />'. 

 Lunaria and others) it is upright and isolateral. Lammermayr once 

 put this to the test, and found that out of 48 growing specimens of 

 B. Lunaria 18 had the sterile frond situated in a N. to S. plane, 17 in a 

 N.E. to S.W. plane, and 8 in an E. to W. This calls to mind the position 

 assumed by the leaves of the compass-plant. 



Zygopteris Grayi.J — B. Kidston publishes a note on the petiole of 

 the fossil Zygopteris Grayi Williamson, with special reference to the so- 

 called " axillary shoot " or branch. He gives a description and figures 

 of the anatomy. 



East African Ferns.§ — L. Cufino gives a list of Cryptogams collected 



by F. Gallina in the Italian colony of Erythraea, and among them the 



three ferns Adiantum sethiopicum, Gheilauthes farinosa, Actiniopteris 



radiata. 



* Bull. Torrey Bot. Club, xxxvii. (1910) pp. 201-3. 

 t Oesterr. Bot. Zeitschr., lx. (1910) pp. 129-30. 

 \ Ann. 3ot.,xxiv. (1910) pp. 451-55 (pi.). 

 § Malpighia, xxiii. (1909) p. 244. 



