312 WALTER GARDINER. 



did occur, and obtained no satisfactory results whatever. 

 Two years ago I made a number of experiments with gold 

 chloride and silver nitrate, and was forced to conclude that 

 they were unsatisfactory for botanical research. In my later 

 work also I have tried many modifications which have met 

 with no success as far as their use for studying the perfo- 

 ration of the cell wall by protoplasm is concerned, and I can 

 only add that the experiments made in connection with Dr. 

 Elsberg's paper have fully confirmed my previous conclusions. 



Before leaving the subject I should like to make a few 

 remarks upon a more important paper, viz. Professor From- 

 mann's " Beobachtungen iiber Structur und Bewegungserschei- 

 nungen des Protoplasma der Pflanzenzellen." ^ 



The only part of his paper that I shall venture to comment 

 upon is that which deals with the perforation of the cell wall 

 and the subject of protoplasmic continuity. His results in 

 this direction may be summed up in his own words, in which 

 he claims to have established " that protoplasmic nets pass 

 from one cell to another, and connect neighbouring cells with 

 one another by means of either smaller or larger gaps and 

 crevices in the membrane." This structure was especially 

 clearly seen in the epidermal and hypodermal cells of the leaves 

 of Rhododendron ponticum and Dracaena Draco, but 

 the leaves of Aloe arborescens, Crocus, Hyacinthus, 

 and Mentha were also investigated. 



I propose to give several quotations from Professor From- 

 mann's paper which will serve to illustrate the exact nature of 

 his statements, and at the same time make it quite clear, which 

 of these I wish to deal with, and to criticise. 



On page 9, when treating of the epidermal and hypodermal 

 cells of Rhododendron ponticum, we find: "The inter- 

 cellular spaces contain nets and granules ;" and further on — 

 " The partition walls, however, do not always completely shut 

 off neighbouring cells from one another, but are i)retty fre- 

 quently interrupted by gaps and crevices which are generally 



' ' Beob. iibcr Structur und Bewcg. d. Protoplasma der Pflanzenzellen,' 

 Jeua, i860. 



