PROTOPLASMIC STREAMING IN PLANTS 



CHAPTER I 



INTRODUCTION 



SECTION i. Historical. 



AT a very early date the attention of scientific observers was drawn to 

 the streaming movement exhibited by the cell-contents of many plants. 

 Thus Corti 1 in 1774 pointed out that the fluid contents of certain aquatic 

 plants and also of some terrestrial ones (Cucurbita, Mercurialis, Solamim, 

 &c.), in all about thirty species, frequently exhibited streaming movements. 

 These observations were confirmed by Fontana, but at the time the exist- 

 ence and character of protoplasm, the basis of all life, was still unknown, 

 and Corti apparently concluded that what he observed was simply a move- 

 ment of the cell-sap, although he noticed that it ceased after the cells had 

 been immersed for some hours in olive oil, and that it became slow at low 

 temperatures, more rapid at high ones. 



These forgotten observations were revived by Treviranus in i8o7 2 . 

 At a later date Amici 3 studied rotation in Chara and considered it to 

 be an electrical phenomenon, the chloroplastids acting as the motor- 

 mechanism. Streaming was also observed by the Englishman Slack 4 in 

 Nitella flexilis and Hydrocharis Morsus-ranae, and by Meyen 5 in Vallis- 

 neria, Stratiotes, Potamogeton, and in the root-hairs of several terrestrial 

 plants. Even before this R. Brown had observed streaming in the staminal 

 hairs of Tradescantia. Slack's figures are remarkably accurate, ' proto- 

 plasm ' nucleus, cell-sap, direction of streaming, indifferent lines, threads, 

 &c., all being shown, but neither this observer nor even Dutrochet recognized 



1 Osservazioni microscopiche snlla Tremella e sulla circolazione del fluido in una pianta 

 ncquainla, Lucca, 1774, p. 127. 



2 Physiologic, 1807. 



3 Mem. della Soc. Ital. delle Scienze in Modena, xvm, p. 182, 1818. 



4 Ann. sci. nat., 1834, " s ^ r -> T. I, pp. 193, 271. 



5 Ann. sci. nat., 1835, ii. se"r., T. iv, p. 257. 



EWART B 



