164 F. 0. BOWER. 



living cell. We may leave on one side the very valuable 

 conclusions as to the connection between turgescence and 

 growth, which he obtained by the use of plasmolysis, since 

 these fall outside my present subject. It is unfortunate that 

 the importance of these conclusions made him lose sight of the 

 structural details, which had already been partially observed 

 by Naegeli and Pringsheim. He even quotes (p. 38) the de- 

 scription of the latter word for word, though in the text he 

 repeatedly ignores his results, speaking of the contracted pro- 

 toplasm as free on all sides (" allseitig frei," pp. 9, 38, &c.). 

 His figures (p. 35) also represent the contracted protoplasm as 

 completely disconnected from the wall, with which it was 

 originally in contact. 



The results of these earlier observations being thus but little 

 taken into account in what is certainly the most important of 

 the more recent works on this subject, it was only natural that 

 for a time no further advance should be made. The description 

 of de Vries and his figures were adopted in text-books subse- 

 quently written, and, as far as I know, there has been no 

 further statement on this subject^ till Gardiner, in a notice 

 communicated to the Royal Society (Nov. 11, 1882), described 

 observations on plasmolysis of cells of the pulvinus of 

 Robinia pseudacacia, which were made in connection with 

 his work " On the Continuity of Protoplasm in the Motile 

 Organs of Leaves."^ He also extended his observations to 

 pulvini of a number of other plants, and also to stems and 

 roots. He found that in a very great number of cases strings 

 of protoplasm connect the contracted protoplasmic body with 

 the cell wall. His attention was naturally attracted to the 

 relation of these strings to the pits, and he found that "in 

 several well-defined instances many threads do go to pits, and 

 also that in two adjoining cells many threads on different sides 

 of the common cell wall are exactly opposite one another." 



Before these observations of Gardiner were published, and 



1 The matter seems to have been entirely overlooked by Pfcffer in bis 

 ' Osmotische Untersuchungen,' and in his ' Pflanzenphysiologie.' 



2 • Quart. Journ. Micr. Sci.,' 1S82. 



