FEETITiTSATlON OF THE EGGS OF ANIMALS. 145 



Is Chemotaxis a Factor in the Fertilisation of 

 the Eggs of Animals ? 



By 



A. II. Ro;;:iiialtl Biillor, B.Sc, PIlD., 



Lecturer in Botany at the University of Birniingliain. 



Contents. 



PAGE 



I. Introductiox ....... 145 



11. Some Fektilisation Pkoelems .... 150 



HI. Material . . . . . . .151 



IV. Kemauks upon the Eggs and Spermatozoa of the 



eciiixoidea ....... 152 



\'. The Chemotactic Question ..... 153 



VI. The Movements of Spermatozoa upon Surfaces . . 159 



VII. The Direction of Penetration of the Gelatinous Coat . 167 



VIII. The Attachment of Spermatozoa to the Egg . . 174 



IX. Summary of the Chief Results .... 175 



I. Introduction. 



The well-known researches of Pfeffer^ have demonstrated 

 the importance of the part played by chemotactic stimuli in 

 causing the spermatozo:i of liverworts, mosses, ferns, etc., to 

 approach the oospheres. Among the yet higher plants — 

 Gymuosperms and Angiosperma — the chemotropism '-^ of 



^ " Loconiotorisciie Kichtun2;sbewegungen durcli cliemische Reize," 

 ' Unlcrsucliungeu aus d. Bot. Inst, zii Tiibingen,' 1881, V>d. i, p. 3G3. 



- Moliscli, " Ueber die Ursaclien der Wachstuiiisriclitiingeu bei Polleii- 

 sclilanclieii," ' Siizungsber. derKais. Acad. d. Wiss. in Wien,' 1889 and 1893. 

 AUo Lidforss, " Uel)<;r den Clieinotropisnms der PollenschUiuche," ' Ber. d. 

 D. Hot. Gescll ,' 1895, Bd. xvii, p. 236. 



VOL. -It), I'AKT 1. — NEW SERIES. K 



