410 Prof. Reichert on the Phenomena of Motion 



exactly the appearance of a granule^ or roundish or oval corpus- 

 cle, lying upon the filament^ as is very frequently the case in 

 transverse folds of smooth muscular fibres. Thus it is clear that 

 the loop, when in motion, must appear as a granule progressing 

 on the surface of the filament, and, lastly, that it must present 

 the microscopic image of a jerking granule, as it may be pre- 

 supposed that the loop, in its continual new formation and dis- 

 appearance, will not always retain the same elevation, and this 

 will cause the appearance of a vacillation of the vertex of the 

 curve or of the apparent granule. 



On the apparent Amalgamation and Coalescence of the 

 Pseudopodia. 



Of the phenomena which, it was supposed, justified the con- 

 clusion that two pseudopodia of the Polythalamia coalesced on 

 touching, the granular movement has already been discussed and 

 its validity disproved. The other evidence adduced may be 

 referred, 1st, to the absence of visible lines of separation during 

 the immediate contact of two actually or apparently simple pseu- 

 dopodia ; and 2nd, to the variability of the configuration of the 

 entire extended radiating complex of filaments under appearances 

 which it was supposed were only possible by an actual coalescence 

 of the filaments. This must be seen, says Dujardin, to remove 

 all doubt that we have to do with a fluid substance, with a true 

 coalescence of the contractile organs. 



In order to estimate correctly the value of this evidence and 

 obtain an unprejudiced notion of the changes of form in the 

 whole system of filaments, the behaviour of two (in most cases 

 only apparently) simple pseudopodia must be studied under 

 diflferent circumstances. Two such filaments lying beside each 

 other longitudinally, or crossing each from any cause, exhibit no 

 line of separation at their point of contact : this is what is 

 directly observed. Does it follow from this that the parts in 

 contact have coalesced ? Certainly not. Every microscopist is 

 aware that under certain circumstances two decidedly solid parts, 

 such as cells or fibres, may lie together so that the line of sepa- 

 ration is not perceived. Some time since, I observed innumerable 

 Amoeba enclosed in an egg-membrane of Tichogonia. Some of 

 them, when flattened, came close together, and at this moment 

 all visible line of separation was wanting ; afterwards their bodies 

 became cylindrical, and then a line of separation made its appear- 

 ance at their point of contact. Is it at all remarkable that the 

 line of separation between two contiguous pseudopodia is not 

 seen, when their outlines are so faintly marked, and they possess 

 an index of refraction differing so little from that of water ? 



The following observations may be made upon two filaments 



