THE PHiEOPHTCEAlf ZOID 7 



fellow-gamete at short range, as soon as these come within the scope 

 of a " chemotactie " or agglutinating influence (Fucus) ; but in a 

 violently agitated medium (as on a rocky shore) the flagella are of 

 little value, and tend to be reduced (Reef -pool forms, Dictyotaceje), 

 as they have been with ultimate complete loss in Florideae ; on the 

 other hand, in perfectly still water, it is evident that their motility 

 will remain the only agency of sexual approximation, and they may 

 prove increasingly useful, and so tend to become greatly exaggerated 

 (as in Chara and Sphagnum), though always remaining distinct in 

 their inherited attributes from the spermatozoa of the animal phyla 

 (Metazoa). 



Literature. 



GuiGN-ARD (1889), Revue Gen. p. 145. 



KucKUCK (1901), Wiss. Meeres. Kiel. p. 177. 



Yamanotjchi (1909), Bot. Gaz. Fucus; (1913), Zanardinia. 



Ktlin (1916), Berichte, xxxiv. 



Retzius (1906), Archiv. for Bot. v. 10; Biolog. Untersuch. xiii. (1906) p. 95. 



Meves (1918), Archiv. Mikrosk. Anat. p. 274. 



Minchin(1912), Protozoa, pp. 52, 82, 84. 



DoFLEiN (1916), Protozoenkunde, p. 30. 



Sept. 1918. 



