Dr. W. Osier on Organisms [June 18, 



displayed by the small free corpuscles at the margins, which, previously 

 quiescent, begin a species of jerky irregular movement, at one time with 

 their pale disk-surfaces uppermost, at another presenting their dark 

 linear profiles (fig. 5, a & b). Not unfrequently, some of these are seen 

 with a larger or smaller segment of their circumference thicker and 

 darker than the other (fig. 5, c). 



Earliest, and perhaps the most plentiful, of the forms are those of 

 a spermatozoon-like shape (fig. 5, d), attached to the mass either by the 

 head or tail ; while, simultaneously, long bow-shaped filaments appear 

 (fig. 5, e), having an enlargement in the centre. Straight hair-like filaments 

 (fig. 5, /) may also be seen, but they are not very numerous. The time 

 which elapses before they begin the wavy movement is very variable, as 

 is also the time when they break away after once beginning it. Eila- 

 ments may be seen perfectly quiescent for more than half an hour before 

 they move, and others may be observed quite as long in motion before 

 they succeed in breaking away from the mass. Commonly it is in the 

 smaller masses, and where the development is feeble, that filaments re- 

 main for any time adherent. The spermatozoon-like forms appear, at the 

 head, on one view flattened and pale, on the other dark and linear 

 (fig. 5, d) ; consequently the head is discoid, not spheroidal. The bow- 

 shaped filaments also present a dark straight aspect when they turn over 

 (fig. 5, 0), and are by far the longest of the forms, some measuring as 

 much as one 900th of an inch. Many intermediate forms between the 

 round discoid corpuscles and those with long tails are met with in the 

 field, and are figured at fig. 5, g. 



Small rod-shaped forms are very numerous, most of which, however, 

 on one aspect look corpuscular ; but in others this cannot be detected, or 

 only with the greatest difficulty ; slight enlargements at each end may 

 also be seen occasionally in these forms (fig. 5, A). 



Usually late to appear, and more often seen in the profuse develop- 

 ments from large masses, are the forms with three or more tail-like pro- 

 cesses attached to a small central body (fig. 5, &). Among the granules 

 it is extremely difficult to determine accurately the number of these pro- 

 cesses, the apparent number of which may also vary in the different posi- 

 tions assumed by the element. As to the ultimate destiny of the indi- 

 vidual forms, I have not much to offer ; I have watched single ones, with 

 this view, for several consecutive hours without noticing any material 

 alteration in them. The one represented at fig. 6 was watched for four 

 hours, that at fig. 7 for five, and the changes sketched. The diffi- 

 culty of following up individual filaments in this way is very great, not 

 only from the ensuing weariness, but from the obstacle the red corpuscles 

 offer to it. 



With regard to the movement of the filaments, this, at first sight, 

 bears some resemblance to that known as the Brownian, exhibited by 



