Some Observations on the Physiology 

 of Cycas-Spermatozoids. 



By 



K. Shibata and K. Miyake. 



In the fall of 1905 one of us 2) has, for the first time, ob- 

 served the living spermatozoids of Cycas revoluta and among 

 others made some experiments on their chemotactic property. 

 The substances used were malic acid, sodium salts of malic 

 and tartaric acids, calcium fumarate and chlorides of potassium 

 and calcium, besides two alkaloid-salts, namely sulphate of 

 atropin and hydro-chloride of chinine. They were used in solu- 

 tions of various concentrations and the results were always 

 negative : i. e. the spermatozoids were found to be quite indifferent 

 towards the chemicals above mentioned. 



We are now going to report the results of our further ex- 

 periments on this subject. The materials were obtained from 

 Kagoshima and Tanegashima in southern Japan. They were 

 sent to Tokyo at the end of September and early in October. 

 The well known capillary method was used and the capillary 

 tube filled with experimenting solution was applied to each 

 freely swimming sperm atozoid. In these experiments we paid 

 special attention to the constituents of the outside medium, i. e. 

 the solution in which the spermatozoids are swimming. For we 

 know from the recent studies of Shibata 8) on the spermatozoids 

 of Pteridophyta and of Knijep 4) on Bacteria that the chemotactic 

 reaction is considerably influenced by the nature of the outside 

 medium. 



D Read before the Tokyo Botanical Society, Oct. 27th, 1906. 



2 > Miyake, Ber. d. Deutschen Bot. Gesellsch., Bd. XXIV. 1906. Also in But. 

 Mag. Tokyo, Vol. XIX. Oct. 1905. 



») Jahrb. f. wissensch. Rot., Bd. XLI, 1905. 

 » Jahrb. f. wissensch. Bot., Bd. XLIII, 1906. 



