PROCEEDIXGS OF THE SOCIETY. 357 



Among the primitive protoplasmic movements there were a con- 

 siderable number of sub-types. Some were entirely intra-cellular 

 without any effect upon the cell-wall. The streaming and circulatory 

 movements within the cells of Anacharis and just under the cell-wall in 

 Closten'um, both of which were being exhibited, were cases in point. 

 Somewhat similar movements could be seen also in many Protozoa. 



Then there were movements produced by the extrusion of various 

 protoplasmic processes or pseudopodia as they were usually called. For 

 example, there was the f oraminiferal or reticularian type of protoplasmic 

 movement in which one found an almost indefinite extension of actively 

 streaming threads which branched and coalesced or anastomosed in a 

 most bewildering way, forming a marvellous living and moving network. 

 Fortunately he was able to show that evening a living specimen of a 

 fresh-water Foraminifer, a species of Microgromia, which, in spite of its 

 small size, illustrated the characteristic reticularian type of pseudopodial 

 movement fairly well, although not to be compared with most of the 

 larger marine forms. 



Another form of these primitive protoplasmic movements was what 

 might be called the Filose-Rhizopodal sub-type. It was somewhat 

 intermediate between the foraminiferal and the truly amoeboid forms of 

 movement to be considered later. On the whole it was nearer to the 

 former than to the latter, but the pseudopodia scarcely ever showed any 

 tendency to anastomose, and they were not as a rule very numerous. It 

 was well seen in such forms as Euglypha, Cyphoderia, etc., of which, 

 however, there were apparently no representatives being shown. 



A better known and more characteristic kind of protoplasmic 

 movement was the Lobose-Rhizopodal or Amoeboid sub-type properly 

 so-called. In this the movement took the form of the extrusion of a 

 number of rather blunt more or less finger-like processes which were 

 continually being given off and reabsorbed by the central protoplasmic 

 mass. The Ammha offered the typical example of this variety of 

 movement, and there were several species of that very protean genus on 

 view that evening. 



Yet another kind of protoplasmic movement was the Heliozoic 

 sub-type in which the pseudopodia appeared like radiating spines, well 

 seen in the specimen of Actinosphserium which was shown under one of 

 the microscopes. It had not yet been satisfactorily explained how the 

 locomotion of the organism was effected by the rigid-looking, though 

 not really rigid, pseudopodia, but movements from place to place 

 certainly occurred, and in some instances rather rapidly. 



A peculiar variety of protoplasmic movement in which considerable 

 change of shape occurred, and yet without extrusion of processes, was 

 seen in such forms as Euglena, Astasia, etc. It might be termed the 

 Euglenoid or metabolic type of movement, and was probably to be 

 regarded as a modification of the amoeboid type due to the presence of 

 a permanent though very elastic cell-wall. Unluckily there were no 

 specimens on view which exhibited this peculiar kind of movement. 



Coming to the types of movement which were not so evidently 

 protoplasmic as the foregoing, but which were somewhat problematical 

 in their nature, they might take first the Diatomic or Bacillarian move- 



