PROCEEDINGS OK THE SOCIETY. 133 



advanced as to the method of locomotion in diatoms — all of them with 

 a good deal of pertinacity — and especially to be noted was the theory 

 put forward by Mr. Jackson, which was commented upon recently in the 

 Journal. All these theories, however, failed to agree with the actual 

 phenomenon. Still another theory had been propounded by R. Lauter- 

 born, namely, that the diatom moved by the protrusion of what he called 

 gallerte, a sort of jelly. 



Lauterborn referred to Surirella as moving because of the streaming 

 (if gallerte in the keels. There were four keels occupied by tubes run- 

 ning fore and aft the diatom. Lauterborn said the streaming substance 

 was not protoplasm, since he was unable to find any of the Butschli struc- 

 ture in the contents of the keel. He had also stained it, and had been 

 unable to find any keel protoplasm. This was astonishing, since when 

 properly stained after fixing the protoplasm showed itself very clearly. 

 The slide under the Microscope contained Surirella which had been 

 killed and fixed with corrosive sublimate, and stained with iron-alum and 

 hematoxylin. It showed the protoplasm extending in unbroken con- 

 tinuity through the ribs and the tube of the keel. That which circulated 

 in this keel was most certainly protoplasm, and it moved the diatom by 

 action upon the environment through the minute cleft that ran the 

 length of the keel. 



Mr. Scourfield said that he would like to ask how the protoplasm was 

 supposed to produce the movement of the Diatom, as it did not seem to 

 be very clear. If there were a tube along each ridge he did not see how 

 the protoplasm inside could affect external objects. It was, however, 

 quite certain that something moved along the tubes. Only a few evenings 

 lief ore he had been looking at a living Surirella and saw quite distinctly 

 that small particles of dirt were passed along the ridges, but he could 

 not make out exactly how this movement was brought about. 



Mr. Palmer said that certainly the protoplasm streaming in the cleft 

 of the keel was competent to do this, since it visibly moved particles of 

 debris along this cleft. 



Mr. Scourfield assumed that the protoplasm came out of the cleft in 

 a series of waves, or it might be in a continuous band running along, but 

 certainly projecting somewhat from the surface. 



Mr. Palmer replied that that might be so, but that the protoplasm 

 did not necessarily extend much beyond the surface of the silica, and it 

 was probably clothed with a thin layer of sticky gallerte or jelly at that 

 point, since small particles of external substances adhered to it quite 

 strongly. 



Mr. Shillington Scales said that in regard to Mr. Nelson's sugges- 

 tions on the subject of examination questions upon Microscopy on p. 771 

 of the last issue of the Journal. Mr. Merlin had written a note to Mr. 

 Nelson saying that " he had succeeded in accomplishing th e resolution." 



The Annual Report of the Society for the year 1910 was then read 



by Mr. Shillington Scales. 



