30 QUARTERLY CHRONICLE. 



■which, however, are not surrounded by any cortical sub- 

 stance. From the central mass, as well as from these smaller 

 masses, spring in all directions the colourless, usually very 

 fine, but sometimes coarser, anastomosing threads in which 

 the coloured fusiform corpuscles, either simply or several 

 together, pursue their lazy course. 



Observation shows that by degrees all the globules in the 

 central and other aggregations assume the fusiform shape, 

 and proceed along the filaments until, at the end of several 

 hours, the greater part of them may be observed to have 

 reached the edge of the fluid in which the specimen was 

 immersed. 



The fusiform corpuscles vary greatly both in size and shape ; 

 the latter varying from perfectly globular to that of a thread 

 slightly thickened in the middle. They seem to consist of a 

 homogeneous protoplasmic substance. They are never seen 

 to coalesce. When closely examined the body is seen to be 

 flattened, and without any visible membranous envelope; 

 it represents a mucus-corpuscle, with scattered gramdes and 

 pigmentary particles. In the centre is a nucleus, which ap- 

 pears like a clear vacuole, containing a strongly refractive 

 nucleolus. The colouring matter in its chemical reactions 

 seems to resemble the red spots in Euglena, the Rotifera, 

 Uredinece, &c. 



The motion of the fusiform particles, which, from the de- 

 scription, would appear to bear some analogy wdth that of the 

 granules in Tradescantia, &c., is excessively slow, not ex- 

 ceeding, according to the author's observations, -413-th to -p-Vth 

 of a millimetre in a minute, nor is it very uniform. The 

 principal direction seems to be towards the periphery of the 

 drop of water, but the shortest road is not invariably selected, 

 so that sometimes, missing the way, they return to the central 

 mass from which they had started. With respect to the 

 cause of the motion the author has been unable to make out 

 anything satisfactory. It appears certain, however, that 

 whatever it is, it resides in the corpuscle, and not in the fila- 

 ment, although the former is unable to move, except when in 

 connexion with the latter. 



With regard to the nature and properties of the filaments 

 and the substance of which they are composed, it is re- 

 marked that they are solid, and the substance non-contractile ; 

 consequently, they in noway resemble the pseudopodia of the 

 Rhizopoda. 



The author enters into a long discussion regarding the 

 mode of origin of the threads and their component fibrillee, 

 and the result at M'hich he has arrived is, that the ultimate 



